D&D 5E Let's Make a Monster(s) with the 2014 DMG!

There is an impression out there that the monster creation rules in the 2014 DMG don’t work.

I disagree. I haven’t had any problem making monsters with them, and there are others that can say the same thing. I’ll try to keep my rambling thoughts and theories in the footnotes(1) and focus on the practical process.

Some say the rules don’t work. I say they do(2). I intend to try to prove it. :)

I’m going to make about 5 monsters(3), with little or no pre-planning. I’m just going to think up a monster idea, open up the DMG and MM, and make it happen. And I’m going to tell you what I’m doing and how it relates to the DMG rules every step of the way.

Let's start with the idea that came to me as soon as I had the idea to write this up this morning: the Thwumper.

Monster 1: “The Thumper”​

Step A(4) Come up with a concept for your monster. Resources Needed: Creativity.

If you are planning to create a monster, we can assume you already have sufficient creativity, or you are working on developing it. At this step you just come up with the general concept of your monster in sufficient detail to feel like you can start D&D-ifying it.

The thwumper will be a giant, dome-shaped, many legged, beetle sort of thing(5). I want to give it a special ability that allows it to create a little earthquake thing centered right beneath it, its “thwump” ability.

Step B(6) Come up with an expected CR. Resources Needed: Monster Manual, experience.

For this step, you need to have an idea of what sorts of monsters the various CRs represent. Your best and simplest resource here is a Monsters by CR list. Here’s a link to the official one from WotC.

Decide about how tough you want the monster to be, using that list as a guideline. You either need to have enough experience to know how tough monsters on the list are, or you can just look them up and read their entries in the MM. Once you find the right challenge, you know your expected CR(7).

For the thwumper, I want it to be a pretty scary challenge for low level characters they might rather avoid, but something mid-level characters won’t have too much of a problem with. At this point, I’m also clarifying for myself its size, so I can better visualize it relative to the other monsters. It’s not quite as big as the Huge bull African elephant (itself probably one of the smallest Huge creatures in dimensions, if not mass), but it's pretty big, so Large is the right size.

CR 5 sounds like a good starting point as a scary challenge for low level characters, so I’ll look in that general area on the list. Right off the bat I see a Bulette. That immediately sounds pretty close to what I’m going for. As I look down the list, I also see Hill Giants (feels like about the right power level). So CR 5 is looking pretty good to start.

But I want to be sure so I’m going to look at CR 4 and CR 6. CR 4 has that Elephant, and while this creature is smaller than an elephant, it’s a monster that I see as being tougher. CR 6 is a Mammoth(8), and right in the middle seems like a great fit.

CR 5 it is.


Step C Decide on the stats you know you want. Resources Needed: Monster Manual, Player’s Handbook, experience.

At this point, you may already know what you want certain things in the stat block to be. Look at a monster stat block, and go down the line jotting down stuff you already know you want from the following list: name, size, type, alignment, ability scores, AC (ballpark only), hit points (ballpark only), resistances, immunities, vulnerabilities, equipment, traits, special actions and reactions, speed and movement types, save and skill proficiencies, senses, and languages(9).

Do not do any math at this point. Do not try to figure out how much damage an attack does. Only jot down things you already know you want. And it’s fine to just use estimates.

I already know its name, and that it’s going to be Large. Monstrosity is the best fit for its creature type, as it’s not intended to be weird enough to be an aberration. It’s an unaligned creature.

The Bulette’s AC is 17, but I don’t have a problem going a bit higher than that, and 18 is calling to me, so its AC is tentatively 18 from natural armor.

It should have plenty of hit points, but I don’t see it as having particularly more or less than you would think by looking at it. I look at some other monsters of similar size, shape, and CR, with a particular emphasis on monstrosities. Bulette CR 5, 94 hp; Gorgon, CR 5, 114 hp; Umber Hulk and Young Remorhaz, both CR 5, both 93 hp. And for extra data, Elephant, CR 4, 76 hp; Mammoth, CR 6, 126 hp. I could keep going, but a pretty good pattern is emerging here. About 93/94 is coming up multiple times, and the ones that are higher are supposed to be super tanks (which the Thwumper isn’t), so we have a pattern. I’ll just tentatively jot down 94 hit points, but it could easily go from 85 to 105.

While I was looking at those monsters I also noted AC for Bulette, 17, Gorgon, 19, and Umber Hulk, 18. Knowing what those monsters are, that convinces me. 18 is the right AC.

Nothing stands out for resistances or immunities, though we might spruce it up with something that won’t affect the CR later(11). No vulnerabilities(12). Obviously no equipment.

For special traits, nothing immediately comes to mind, but there’s a good chance I’ll think up something later.

For special actions, we will have the thwump! They can use some sort of sonic effect to cause an earth tremor underneath them that can knock down nearby creatures. Maybe it will do some damage too, maybe it won’t. We’ll wait and see. I’m thinking that if it does damage it will be an action, and if it just knocks them down it will be a bonus action. In any case, it will be on a recharge for usage. We don’t want any math here yet, though if we had a monster that already had a similar attack and we wanted it to be almost exactly the same, we could jot down a ballpark damage figure. No reactions come to mind.

For speed and movement, I don’t imagine it as being particular fast. In fact, I kind of imagine it as being slower than normal, but that might not be a good idea, because it means characters can just walk backwards and kite it until it’s dead, making it much weaker than it should be. We’ll worry about that later, just noting the potential issues. Should it have a burrow speed too? Probably!

While I was thinking about the speed, I thought of a similar critter from Fell Seal that has this charge that lets it move any distance. Charging any distance doesn’t make sense here, but having some sort of charge attack (maybe rolling into a ball to do it?) sounds cool, and I put it down as a potential option.

I don’t have many thoughts on save proficiencies at the moment so nothing to write down. For skills, maybe Perception, but we’ll think about that later(13). For senses, tremorsense sounds good. Maybe we’ll make it blind and give it blindsight too, maybe not. It’s an unintelligent, unaligned creature; it doesn’t speak any languages.

I noticed that I forgot to jot down any ability scores. That’s actually fortuitous, because during the AC and hp steps I looked up some reference point monsters, so I can look at their stats for ideas. Bulette: Str 19, Dex 11, Con 23, Int 2, Wis 10, Cha 5. Gorgon: Str 20, Dex 11, Con 18, Int 2, Wis 12, Cha 7. Umber Hulk: Str 20, Dex 13, Con 16, Int 9, Wis 10, Cha 10. Young Remorhaz: Str 18, Dex 13, Con 17, Int 3, Wis 10, Cha 4. For the beasts, Elephant: Str 22, Dex 9, Con 17, Int 3, Wis 11, Cha 6. Mammoth: Str 24, Dex 9, Con 21, Int 3, Wis 11, Cha 6.

For Strength, I don’t see it having the ability to exert a lot of musculature in its attacks, so it should be average or a bit below average for its size, shape, and CR. But I also know I don’t want to go too low because it will be using this for its attacks (I don’t want its thwump to be its standard round by round attack). I’m going to tentatively place it at 18, the same as the lowest one on the list, the Young Remorhaz. Might change it later.

For Dexterity, it’s looking like we want something between 9 and 13. It’s also possible we could go even lower. So I’m just going to jot down “not high” for this, because I know that much.

For Constitution, it should be at least average, but it doesn’t need to be super high. It should probably be at least 17, but I don’t have a firm upper limit on it. That’s good, because we can tweak it to the best place to get our derived stats later. I’m going to jot down 17-22.

For Intelligence, I definitely don’t want it above 2. But it is insect-like, and I know they often have an Int of 1. Since I have a spreadsheet of some monster stats(14), I check out which ones have an Int of 1. I still have my size Large filter on, and I see that Ankheg and Carrion Crawler are both monstrosities with an Int of 1. Yeah, that’s it, Intelligence 1.

For Wisdom, an important thing to remember is that it effects the ever important Perception—though you can counteract a low Wisdom with proficiency or double proficiency (“Expertise”) in Perception if you want to. Nothing really stands out to me about this creature’s perceptive abilities, so I’m going to leave it at the average of 10 or 11.

Charisma can be a bit tricky, because oftentimes creatures that are more magical or supernaturally scary and such might have good Charisma, as well as any creatures who base special abilities off it. The Thwumper doesn’t have to worry about any of that, so I’m going to look up Carrion Crawler and Ankheg, for the bug similarity, which gives me 6 and 5. (I also note that they have Wisdom scores of 13 and 12, so maybe I should go higher there.) Looking at the Charisma of the other creatures, I feel like a 6 is probably appropriate here as a guess. It’s not really going to matter for this creature, so I can adjust it later for pure statblock aesthetics if I want to.

I also didn’t think of what its Burrow speed should be, so I just looked up the burrow speeds of other creatures. Those who are supposed to be ridiculously good at burrowing have it equal to their walk speed, those who are pretty good have it a bit less, and those that are more natural creatures (like badgers) have it at a pretty low number. I see the Thwumper as being in the middle, so it should probably be a bit slower than its walk speed—unless its walk speed is lower than 30, in which case burrow should probably be equal so it stays meaningful. So that pretty much means it should be 20, as its walk speed isn’t going to go below that.

So before we even mess with the math, we know the following with a pretty high degree of certainty(15):

Thwumper
Large monstrosity, unaligned.
AC 18 (natural armor)
HP 86-100(10)
Speed 20 or 30, Burrow 20
Str 18
Dex not high
Con 17-22
Int 1
Wis 10
Cha 6


Special Action or Bonus Action 1: Thwump. The creature emits a sonic burst that causes a tremor in the ground below it. All creatures other than the thwumper within X feet must make an X save or be knocked prone, and maybe take XdX bludgeoning damage.

Special Action 2: Some sort of charge. The thwumper moves up to X feet directly towards a target and makes an attack (or forces a save) dealing XdX bludgeoning damage on a success.

That’s a pretty darn good start and we haven’t had to do any math yet(16)! Which brings us to…


Step D Determine the math so far. Resources Needed: Monster Statistics by Challenge Rating table, DMG Step 4 of “Creating Quick Monster Stats”, DMG Steps 9 – 15 of “Creating a Monster Statblock”, Monster Features table.

Now we determine what the things we already know we want the monster to have tell us about the math so far. It’s really straightforward once you understand how it works, but it will be easiest to explain by using our example.

For the Defensive CR, we know that the Thwumper’s hit points will be between 86-100, which puts them on the CR 2 line of the table. We now adjust that CR based on their AC. Their AC is 18, which is 5 points higher than the AC 13 that the table associates with CR 2. Every two points by which the AC exceeds the hit point line increase the Defensive CR by 1. Since we have increased it by 2 twice, we increase the CR by 2.

The Defensive CR can also be influenced by five other factors:
1) If the monster has 3 or more damage resistances and immunities(11)
2) If they have any spells that can affect their AC(17)
3) If the monster can make ranged attacks while flying
4) If the monster has 3 or more saving throw proficiencies
5) Special traits, such as those on the Monster Features table(18)

None of those apply to the Thwumper at this point. We already know 1-4 will not be used, and since we haven’t chosen (or created) any defensive special traits, we can jot down their current Defensive CR as 4. If we make any defensive traits, they could raise it.

We don’t have enough information at this point to come up with an Offensive CR so far.
Much of the time you won’t at this point. The main exception is if you are using an equipment-based creature and you know its attack stat. Then you could combine the weapon’s damage, with the attack stat from the damage, how many attacks it gets a round, the proficiency bonus from its expected offensive CR, and use the table to determine what the actual current Offensive CR is(19).

What we can do is note the math that will help us determine it later.

With Strength-based attacks, our Strength score of 18 and the proficiency bonus of +3 from a CR 5 creature tells us that its attack bonus will be +7. We also know that we will be adding +4 to the damage from the dice value we use for its attacks.

For the save DC on its thwump ability, Constitution is the best stat to use. We imagine this sonic thwump thing coming from its monstrous anatomy not its mind--which is good because its mental stats are not combat worthy(20). It will probably be equal or higher than Strength, so it has the benefit of also using it’s highest value. We want this to be a good special attack!

Its Constitution is going to be 17 to 22. Using the save DC formula (8 + proficiency bonus + ability score modifier) we know the save DC against its thwump is going to be 14 to 17.

The ability to knock creatures down has no effect on the CR normally. However, if we make it a bonus action and let them use it before it makes its attack(s) for the round it could grant it advantage on its attacks for the round, which would increase its effective attack bonus by 4 for that round(21). We still haven’t decided whether its going to be a bonus action that doesn’t cause damage, or a standard action that does, though I’m leaning towards the latter.

For its charge ability, it will be Strength-based, so it will either have an attack bonus of +7, or a Save DC of 15.

So what can we tell regarding the Offensive CR at this point? Well, since the Defensive CR is 4, that means we need an Offensive CR of at least 5 to hit the overall CR of 5 we want. Unless its saving throw abilities end up be more contributive to its damage output than its attack, we can now use the table to determine what range its per round damage should fall within it. The attack bonus for the CR 4 damage line is +5, so if we used the CR 4 damage, our +7 would be 2 higher and raise it to a CR 5. Or we could just use the CR 5 damage line, which has an attack bonus of +6, so our +7 wouldn’t raise it. That means the damage output per round should be 27-38.

And that’s about all we can or should determine about the math so far.


Step E Experiment with attacks, traits, and special abilities. Resources Needed: All of the above.

This step could be long or short, depending on how complex your creature is and how much you already figured out about their stats in Step C. Essentially, we want to see if there are any traits or features we might want to give them that haven’t occurred to us yet, create possible stats for their damage, as well as any other actions, bonus actions or reactions.

Whenever you pick or choose potential features (such as from the Monster Features table) that have an effect on CR, you want to make a note of what that effect does, such as “Fiendish Blessing: Cha mod to AC”. Don’t apply those effects yet, just determine what they will do if you do apply them.

By the end of this step, we should have all the components we need to finalize the creature’s CR relevant stats in the next step.

For the Thwumper, we know we still need a few things. For the first, I want to see if there are any special defensive features I might want to give it. Brainstorming, I would kind of like the ability for them to withdraw into their shell and increase their defenses. Maybe they even can (or must) do it at the same time they activate the thwump ability.

Off the top of my head, I can think of two creatures that can do that, the Flail Snail, and the Tortle(22). I’ll use them for the template for this ability. I’m not sure if it needs to grant the full +4 AC, since this creature is mostly in its shell all the time, so I can drop it to 3 or 2 in the future if that would help with the math.

Shell Defense (Action): While standing on solid ground(23), the thwumper withdraws into its shell. Until it emerges it gains a +4 to AC and has advantage on Strength and Constitution saving throws. While in its shell its speed is 0 and can’t increase, it has disadvantage on Dexterity saving throws, it can’t take reactions, and the only action it can take is a bonus action to emerge.

This feature will do absolutely nothing to the creature’s CR, since it isn’t doing anything offensive on turns it spent its action to hide in its shell. Using this feature is an ineffective action choice that would actually reduce the monster’s challenge the vast amount of the time. But it’s there because it makes sense and seems cool(24).

Looking through the Monster Features table for possibilities and inspiration, I don’t see anything else there on the defensive front that makes sense. However I do note the Tunneler trait from the Umber Hulk that I like. It doesn’t effect the CR either. Let’s put it in.

On to the Thwumper’s offensive features. We could do this in any order. I’m going to start with their standard round by round attack.

We’re aiming for a damage output of 27-38, and we need to include a +4 from Strength to each attack as part of that. I’m planning on splitting that between two or three attacks.(25)

To start, I’m going to look at physically similar attacks from other large creatures. An Ankheg’s bite does 2d6 + mod damage. An Umber Hulk’s mandibles do 2d8 + mod, and its claws do 1d8 + mod each. Three attacks along those lines will get me into the right damage range, so sounds good! I don’t want to give it any pincers, but maybe some slashing claw legs to go with its mandibles. Let’s try putting that together as:

Multiattack. The thwumper makes three attacks: two with its slashing legs and one with its mandibles.

Slashing Leg. +7 to hit, reach 5 ft, 1d8 + 4 slashing damage.

Mandibles. +7 to hit, reach 5 ft, 2d6 +4 slashing damage.


That gives us 28 damage, putting us on the CR 4 damage line, which goes up to CR 5 with our attack bonus.

Offensive CR takes the average damage from three rounds. They will bite on two of their rounds, and do their thwump on the other one. Note that since we are on the lower side of our damage, we can feel free to make that thwump more dangerous. The maximum damage we can do with the thwump without raising the Offensive CR for that round above 6 (which would still leave them at an overall CR of 5) is 22. Since it’s an area of effect attack, we assume it hits two characters for a total damage of 44, with a maximum save DC of 16. Note that we most certainly are allowed to raise the Offensive CR above 6, since the damage is for a single round and will be averaged with the damage of the other rounds. I just wanted to demonstrate how the math and the table were intersecting.

Off the top of my head I can’t think of any creatures that do this effect. The earth tremor spell is the closest similar effect. Although spells love to do d6s for damage, I want to make the damage more random on this, so I’m going to use bigger dice.

Thwump. The thwumper sends shock waves into the ground in a 5 foot radius. Each creature on or under the ground other than the thwumper in that radius must make a DC (15 or 16) Strength saving throw or take 4d8 bludgeoning damage(26) and be knocked prone. Creatures that succeed on their saving throw take half as much damage and are not knocked prone.

Note that I made some conceptual decisions as I wrote that up. I decided I didn’t want it to turn the earth into difficult terrain. I also wanted to make sure they were taking some damage even if they made their save. And that implies to me that this isn’t purely a normal earthquake. There is some sonic stuff going on there that kind of resonates with the ground and anyone on it. I could split up the damage into bludgeoning and thunder, but I don’t think that’s entirely necessary. It’s still really the ground that’s directly messing with you, but it’s messing with you even if you manage to not fall down. But I made the save Strength instead of Dexterity, because I think that better expresses how this unusual attack is affecting its targets. You could go with Dex or Con instead if you really wanted to.

A brief note on knocking a creature prone. Remember how I said early in the post that if that’s all it did it would be a bonus action? That’s because knocking creatures prone as an attack rider doesn’t affect the CR. This is almost certainly because characters can just stand up at the start of their turn, just losing a bit of movement. But if I could use a bonus action to potentially knock multiple creatures prone, and then attack them, I’d be giving myself advantage, which very well could affect the CR(27). I decided to keep it simpler and just have a damage + prone ability as the thwumper’s action for the turn. In this case the prone status doesn’t affect CR.

I have some other thoughts about what I might do with this attack, but I’m going to work on some other stuff and come back to it.

Moving onto the charge attack, I realize I need to make some conceptual decisions. How agile do I want the Thwumper to be? While the inspirations were pretty slow and unwieldy I can blame some of that on 1980s special effects(5). I could probably keep its speed at a lumbering 20 and come up with innovative ways to make up for it with special abilities, but I don’t think I’m going to go that route. On the other hand, I could make it a very agile creature, probably with a Climb speed, and have it turn into a potentially bouncing bowling ball kind of thing. I’m not really wanting to go that far in that direction either. I’ll probably stick with a walk speed of 30, a burrow of 20, and possibly a climb (also 20). I have a hard time seeing this creature be able to just have massive bursts of running speed, so I think I might go with the curling into a ball charge.

Rolling Charge. The thwumper launches itself forward across the ground in a line 60 feet long and 10 feet wide, rolling into a ball as it does so. Every creature within that area must make a DC 15 Dexterity saving throw or be knocked prone and take 5d10 bludgeoning damage.

In this case I made the save DC Strength-based. I looked up the Rolling Ball trap in the DMG for some thoughts, and noticed they made it a Dex save with no damage on a success, so I went with that. As an area effect we assume it hits two targets. And while it’s not in the monster creation section, the DMG rules on spell damage say that if you take no damage on a successful save the spell’s damage can be 25% higher for the same level. Total damage of this spell against two targets adds up to 55, and dividing that by 1.25 we get 44 for the effective damage I’m going to plug into the chart. That leaves this as another CR 6 offensive ability. So far that’s 2 out of 3 of offensive abilities are CR 6. That’s perfectly fine, because we could do Offensive CR 6 abilities every round and still hit our creature target CR of 5.

Something that has been rolling around in my mind, with the current concept of the thwump ability, is the idea of stunning the targets. That definitely should make the ability more powerful if it actually prevents characters from acting, but if I have it end at the start of each target’s turn, it will really only stop them from taking reactions. While situationally useful, those situations are going to be rare enough in context of this monster’s normal usage that it isn’t going to raise the CR. Since it really adds some more flavor to the thwump, let’s do it. Also, with that change, Strength no longer makes sense as the save, and we are squarely in the Constitution save territory.

I kind of want to give them immunity or resistance to acid. There’s no really good reason for this. Ankheg’s do acid damage and they aren’t even resistant. But something about it sounds interesting. So I’m going to do it and come up with lore justification later. A single resistance or immunity has no CR effect.

Looking up some monsters with tremorsense, the range is typically 60’ feet, so I’ll go with that. I don’t see any compelling reason to give them darkvision, but pretty much all monstrosities have it, including bulettes, ankhegs, etc, so they’ll get 60’ darkvision.

As I’ve gone through the process, I’ve decided that it’s probably fine if walk speed is 20 ft, given the other things they have; and they don’t need a climb speed.

This step is where you would also be making multiple versions of features if you aren’t sure exactly how you want them to work, or you aren’t sure if the math is going to go how you want it. For example, I could have made a higher damage version of their multiattack routine, or a lower damage version of their Rolling Charge, but I think they will work fine the way they’ve already turned out. This one has coalesced pretty well, but I might end up making multiple versions of things at this step on some later monster.

Those are all the bits and part we need for the Thwumper, so let’s put it all together properly.


Step F Assemble all the components for a desired overall CR. Resources Needed: Monster Statistics by Challenge Rating table, DMG Step 4 of “Creating Quick Monster Stats”, your previous notes.

Now we take all those components we created in Step C and Step D, and put together a monster. Where you have multiple options to work with, you select the ones with the math to give you the CR you want(28). This is also where you will finalize ability scores, hit points, and any derived values.

Notice that at this point, you won’t be referencing the DMG other than to look at that table (and to remind yourself about the Defensive and Offensive CR adjustments in DMG Step 4 if you haven’t internalized it yet.)

Let’s go right down the monster statblock for the Thwumper and fill in everything.

Thwumper
Large monstrosity, unaligned.
AC 18 (natural armor)


For hit points, we’ll need to determine their Constitution score and hit dice. Looking at how it affects the saving throw DCs of their special abilities, I think we want either a +4 or +5 modifier. Comparing it with those other monsters I made notes on in Step C, I’m thinking +4 is what I want, so Constitution 18. As a large creature it uses d10s for HD. And since the range we want it 86-100, we just math it a bit to see which numbers of d10+4s end up in that range. Turns out, there’s only one that does, 10d10s, for 95 hp.

For Dexterity, it ended up back in the lumbering category, and I see it as less agile the the Dex 11 Bulette. The Elephant and Mammoth have Dex 9, and it definitely isn’t any more agile. Let’s just put it at Dex 8, statistically identical but conceptually lower.

I remember now that I left Wisdom at 10 and planned to think about it more later. Later is now. Since the Ankheg and Carrion Crawler had Perception proficiency, I want to make sure that isn’t a universal “bug” thing, or a universal bug-monstrosity thing. I do a quick check on various bug-like monsters, and learn that many do and many don’t. I don’t see perception as being a strong point for the Thwumper, so there is no need to give it proficiency, or increase its Wisdom any further.

HP 95 (10d10 + 40)
Speed 20’, burrow 20’
Str 18
Dex 8
Con 18
Int 1
Wis 10
Cha 6


I liked the idea of damage resistance to acid. Heck, let’s make it immunity and figure out an excuse later.

With no special defensive features, our Defensive CR stays at 4.

To determine the Offensive CR, we need to average the total damage output over three rounds. We’ll assume it uses its special attacks on two of the rounds, and its multiattack routine on one, for an average total damage of 36. That puts us at the CR 5 damage line. Since its damage output actually relies more on saving throws than attack rolls (over the course of three rounds at least) we compare its save DC to the table, and they are on the same line, so no adjustments. That puts its offensive CR at 5. Averaging Defensive CR 4 and Offensive CR 5, rounds to an overall CR 5.

Damage Immunities acid
Senses darkvision 60’, tremorsense 60’, passive Perception 10
Languages –
CR 5

Tunneler. The thwumper can burrow through solid rock at half its burrowing speed and leaves a 10’ wide, 10’ high tunnel in its wake.

Actions

Multiattack. The thwumper makes three attacks: two with its slashing legs and one with its mandibles.

Slashing Leg. Melee weapon attack, +7 to hit, reach 5 ft, , one creature, 8 (1d8 + 4) slashing damage.

Mandibles. Melee weapon attack, +7 to hit, reach 5 ft, one creature, 11 (2d6 +4) slashing damage.

Thwump (Recharge 5-6). The thwumper causes shock waves in the ground in a 10 foot radius. Each creature other than thwumpers on or in the ground in that radius must make a DC 15 Constitution saving throw or take 4d8 bludgeoning damage and be knocked prone, and stunned until the start of their next turn. Creatures that succeed on their saving throw take half as much damage and are not knocked prone.

Rolling Charge (Recharge 6). The thwumper launches itself forward across the ground in a line 60 feet long and 10 feet wide, rolling into a ball as it does so. Every creature within that area must make a DC 15 Dexterity saving throw or be knocked prone and take 5d10 bludgeoning damage.

Shell Defense: While standing on solid ground, the thwumper withdraws into its shell. Until it emerges it gains a +4 to AC and has advantage on Strength and Constitution saving throws. While in its shell its speed is 0 and can’t increase, it has disadvantage on Dexterity saving throws, it can’t take reactions, and the only action it can take is a bonus action to emerge.


Notice that I increased the radius of its thwump to 10’. I don’t think that will break anything, and fits better with what I’m going for. I also made the recharge of the Rolling Charge less than that of the Thwump. This is purely a conceptual choice. While I like giving it that charge ability, and think it works really well for it, I don’t want it to overshadow the thwump that is part of the creature’s original conceived identity.

Now, with those all put together, we can compare the Thwumper against some of the other CR 5 monstrosities we referenced, and see how it feels.

Comparing it to the Bulette, the Thwumper has slightly better defenses, and slightly worse offenses. It is also a lot slower than the Bulette. Compared to the Young Remorhaz, the Thwumper has significantly better defenses, and about equivalent offenses, though the Young Remorhaz is even more punishing on characters attacking it in melee which might push it higher in offense. The Umber Hulk has similar values for defense and offense, but with less flexibility in attacks. It also has a powerful disabling ability it can use basically at will. Since the Thwumper had to round up to get its overall CR 5, we can assume its one the weaker side of its CR. The Thwumper clearly fits as a CR 5 monstrosity. Compared to the other CR 5s, it is stronger than the Young Remorhaz, on par with or slightly weaker than the Bulette, and pretty clearly weaker than the Umber Hulk with its Confusing Gaze.

If I wanted it to be stronger for its CR, I could give it 1 or 2 more HD, which would move its Defensive CR to 5, still keeping it in the same overall CR 5. But comparing it to other monsters, it feels more like I envision the creature to keep its hp where they are.

Mathematically, the Thwumper is complete.


Step G Polish until it shines. Resources Needed: The results of Step F, creativity, experience.

Here is where we take all of that, smooth off any rough edges, polish up the language to read like a proper 5e statblock, and put any lore and/or art we want to go with it.

As we’re doing so, we can make last minute tweaks, or even go back into a previous step and change our design if we aren’t liking how it all looks when we put it together. You want to have a good idea of how the monster looks and functions overall by the time you are done.

For our Thwumper, the only statistical rough edge to smooth is that I’m going to bump up its even 18 Con to the statistically identical 19 Con because I like it better there.

You'll also note that I removed any vestiges of sonic-ness to its thwump attack, and just referenced vibrations, which is really what I was going for all along.

As I was reviewing the final write-up, I decided I wanted to increase the damage on the thwump attack a tad. By raising it from 4d8 to 5d8, the Offensive CR goes up to 6, which doesn't change the overall CR of 5.

I also need a less comical name for the creature and its signature attack, and some skeletal lore(29).


tremorbeetle.jpg


(1) Heh. Let’s see how well I do.
(2) I do not mean that they are simple, 100% straightforward, or that there is no learning curve. Nor do I mean that there aren’t a few rough spots (which I will address as they come up), nor that the presentation in the DMG is done well. But they do what they are primarily designed to do: tell you what the CR of this creature you just made should be, and create monsters that perform approximately at that CR, within a reasonable margin of error. I’m also not claiming that I will perfectly explain it. Feel free to bring up any “What about”s or “You’re totally not addressing”s. Chances are I have taken that into account but I didn’t think to mention it.
(3) Assuming I don’t run out of steam and never get back to it, which happens more often than I would like.
(4) I’m using letters rather than numbers here, so I can refer to the numbered DMG steps with less confusion. Also, as will become obvious, I am not doing it in the exact same order as the DMG does it, because I think my way is more efficient. Nonetheless, I’m using the same math and the same rules.
(5) I’m imagining something like the creatures from The Dark Crystal or The Neverending Story 2.
(6) Before we move forward, you should to know something the book doesn’t explicitly say, and I think might trip some people up. While we are using the “Creating a Monster Stat Block” rather than the insufficient “Creating Quick Monster Stats” rules, “Creating a Monster Stat Block” rules actually are expansions of the other, not pure replacements. You need to read the quick rules first, and you will refer back to them repeatedly.
(7) You might end up moving it up or down by 1 as you get into the details, but if it's a monster you are creating from scratch you probably won’t need to. If you are converting a previous edition monster and want to make sure its CR has a certain relation to monsters of previous editions, or it has an attack that has to do a certain amount of damage for consistency with other monsters, this can become more likely.
(8) Since it’s 2 CR higher than the elephant, I assume we should be imaging the biggest, probably historically inaccurate mammoth we can, rather than the real world ones which probably weren’t 2 CR higher than an elephant.
(9) Those are the order the DMG has them, but you might want to make the list in an order that works better for you.
(10) With my experience, I went back and looked at the table and noted that the hp line that fits the best is the CR 2 line, 86-100 hp, so that’s the value I’m jotting down for hp: 86-100. I wouldn’t have to do that at this point, it just might save me a bit of time later.
(11) Here we’re going to address a rough spot in the rules, the Effective Hit Points Based on Resistances and Immunities table. It’s utter crap. Don’t use it as written. It assumes both that parties will have less ability to overcome damage resistances than is a reasonable assumption, and that characters who can’t overcome damage resistances won’t have any useful way to contribute (and grappling, shoving, or the Help action are a bare minimum of contribution available to anyone). I won’t offer my own replacement for that table yet, both because it’s not finished and because I’m sticking with the rules in the DMG. Just know that if you use those rules the monster will be weaker than its CR indicates.
(12) Vulnerabilities are sort of “advanced design” and you can and should almost never use them unless you have a lot of experience.
(13) Personally, I’d probably give something like this Athletics to help resist grapples and shoves, but I’m not telling people how to make monsters with all my tweaks, I’m going by the book, so no skills unless we decide to give it Perception later.
(14) Not necessary, but it sure speeds things up!
(15) There is of course always the possibility something will change later, and since such changes will likely be for the better, I’ll call that the “happy possibility”.
(16) You’ll notice that even though I said “ballpark only” for some of the things we were figuring out on this step, I actually ended up pretty firm on some things. Once you have a little experience using the system, you learn what things you can and can’t set more firmly at this point. In this creature’s case, it was the AC. It wouldn’t be the same for everything.
(17) This is another rough spot, because they don’t actually tell you how spells affect their defensive CR. If such a spell changes their AC for the duration of the fight, it’s pretty straight forward. For spells that do something else, you need to refer to the Monster Features table to get an idea of what sorts of features adjust the defensive CR in certain ways. For example, the Parry ability which allows a monster to increase their AC against one attack as a reaction increases their effective AC by 1, and the Superior Invisibility Trait, which will impose disadvantage on most attacks against them increases their effective AC by 2. It would be great if there were a table listing specific manipulations like that and how they effect the math, but unfortunately they didn’t give us that.
(18) If you make up your own special traits, you will need to use your own experience and judgment to determine its effect, see note 17. I’m not going to argue with you if you complain about this rough spot.
(19) Another exception is if you are converting a monster or for some other reason already know how much damage it is going to deal, and the ability scores that would affect the attacks or saving throws.
(20) You need to keep that in mind for saving throw DCs. It’s important (at least for me) that the stat used makes sense—you don’t just pick the highest stat because it gives the biggest number. At the same time, you have to fluff it in such a way that you aren’t using an ineffective stat for it, unless it is intended to be something that rarely works in combat that you just turned into an ability for completeness or flavor (which I approve).
(21) See Nimble Escape. This trait is one of the rough spots. It only works as intended for “Forest Archer Goblins”, who can use it to hide behind a tree and take a shot each turn, granting them advantage on all their attacks, and the character disadvantage on all attacks against them. It is significantly weaker in most real game situations, where the goblins might be in melee, or might not be able to hide as easily, etc. However, it does tell us what advantage or disadvantage are worth for monster design: +/-4.
(22) Unfortunately, neither of these are in the Monster Manual, which demonstrates that the more money you give WotC, the more likely you are to be able to figure out how to use the materials you’ve already bought. Hmm.
(23) I put this little caveat in because it can burrow and this shouldn’t work while burrowing.
(24) Advice for running the monster in its write-up should probably tell the DM that this feature is highly situational and shouldn’t be used most of the time.
(25) One of the unstated best practices of monster design is that you should avoid making monsters dependent on a single powerful attack. The reason for this is that it is just too easy for a party to negate that single attack with class features meaning that monster did basically nothing that round. It’s better to make sure they somehow get multiple attacks, even if you need to use bonus actions or reactions to do it. This doesn’t apply to low-level mooks like goblins and orcs and such, and other creatures that are intended to be fought en masse.
(26) Special abilities like this don’t typically add an ability modifier to damage.
(27) This is another rough area in the rules. The same principle would apply if the creature could make multiple attacks in a turn with a prone rider, but the rules don’t account for it. In this case, it doesn’t matter because my creature doesn’t have anyway to attack prone creatures before they have a chance to stand back up.
(28) If you aren’t committed to a specific overall CR, you can just pick the options that give you the math you like best, and take whatever CR you end up with. Theoretically there is a problem with the way the Monster Statistics by Challenge Rating table works. The table depends on your final CR by virtue of using your proficiency bonus (derived from your final CR!) but actually creates the CR at the same time. There is a circular reference that could be a problem. However, I’ve found in practice, since proficiency bonus only changes every 4 CR levels, that that has never actually been a problem. It comes up too rarely to be a significant functionality issue.
(29) I actually prefer lots of lore and multiverse integration on my monsters (2e FTW!), but I’m not going to do that here.
 

log in or register to remove this ad


TLDR:
  • Every step needs experience.
  • You used MM monsters as your starting and comparisons points.
  • the whole procedure is so long that it is probably not worth the effort.

I think you showed very well how not useful those guidelines are for most people.
Exactly. It's not that the rules don't work. You can make them work. But to make them work, you already need to understand how the monsters in the MM are put together already and then use that (and the rules) to inform your decisions.
 

TLDR:
  • Every step needs experience.
  • You used MM monsters as your starting and comparisons points.
  • the whole procedure is so long that it is probably not worth the effort.

I think you showed very well how not useful those guidelines are for most people.

Exactly. It's not that the rules don't work. You can make them work. But to make them work, you already need to understand how the monsters in the MM are put together already and then use that (and the rules) to inform your decisions.

Let me start by partially agreeing with the last points, then address the others briefly.

The main problem with the 2014 DMG monster creation rules is organizational. In that sense, they are a microcosm of the 2014 DMG in general. All of the stuff is there, but if you aren't very familiar with it you may miss it or not know how to find it. And even when you are very familiar with it, it can be a struggle to find exactly that rule you know was in there...somewhere, kinda by that other rule, what was it called?

But, that isn't really the argument I was responding to, and that some people have made. The argument I was responding to was to the effect that the math doesn't match up to the created monsters, that the rules "don't work" mathematically to create the sorts of monsters that the 2014 MM gives us. This isn't accurate, and appears to be based on not being sufficiently familiar with the rules, such as only looking at the table at the beginning and expecting it to make sense in isolation. Again, the failure of organization makes this understandable. But, in fact, it does work once understood. Calculus "doesn't work" for me, because I never learned it, and would probably require a pretty big learning curve to do so at this point. But I am pretty confident that the math absolutely does work for those who have taken the time to understand it.

Why does this matter? If these are simply advanced rules that work for the highly experienced DM who reads and retains the information, then surely we don't need them (as WotC seems to believe). (Although I would propose that better organization would make them more accessible to less experienced DMs--maybe I'll attempt to put a better presentation together.)

It matters because the alternative presented in the 2024 DMG (which is just an expansion of some guidelines already given in the 2014 DMG just before the actual monster creation rules) is wholly inadequate to actually create novel monsters. How could I have ever come up with my Tremor Beetle using the 2024 guidelines? Bulette is the obvious starting point, but there is no way I could have tweaked the bulette according to the 2024 guidelines and come up with what I wanted. And that's a monster that has something not too terribly statistically removed from itself as a starting point. If I were to make something completely different than anything that already exists, I would have no starting point, no way to develop it, and no way to know what CR it is.

What will the 2024 DM do without access to these rules? Sure, you can go on ebay and find physical copies of the 2014 books still, but WotC isn't publishing them anymore (even in digital format), so a DM that starts in a few years and want to make monsters is pretty much out of luck. (I'm veering off of the point of this thread now, so I'll stop).

I'm going to end this reply and post the next monster: the Yuki-on-na.
 

It matters because the alternative presented in the 2024 DMG (which is just an expansion of some guidelines already given in the 2014 DMG just before the actual monster creation rules) is wholly inadequate to actually create novel monsters.

Yeah, this is why I will loudly complain about this glaring omission until it's been rectified. It's honestly exceptionally disappointing that they didn't include an updated CR chart for 2024 at least. They have these numbers.
 

Monster 2: Yuki-on-na

For this monster, I'll be converting a monster from 2e and 3.0e. Converting monsters can actually be more difficult than making new ones, so we'll see how long it takes.

Along with that thought, I'm not going to bother with organizing steps this time. I may try to work up some more concise and accessible steps for monster creation, and using different tactics might help with that. For this monster, I'm just going to do it in whatever order makes sense to me at the moment, but I'll tell you what I'm doing so you can follow along. That being said, I may call out some steps or other monster creation rules in an unorganized manner as I go through them.

The yuki-on-na is found in the 2e Kara-Tur appendix of the Monstrous Compendium, and the 3.0e Oriental Adventures supplement (which gets it's name from a 1e supplement which did not includes this monster, and therefore is not used for this conversion).

The first step to creating any monster is to look at existing similar monsters for reference. To find similar monsters, you really need a way to look them up by CR, and preferably something that can be sorted by size and type. Those three elements are the most important reference elements for finding similar monsters.

Since it's a converted monster, and I want to convert over the same concept, I need to find it's CR (or HD/experience granted) in previous editions, and then find similar monsters with the same CR that also exist in 5e and compare their CRs.

The yuki-on-na is CR 4 in 3e, and 2,000 xp in 2e. My thought for 5e fey in that general ballpark is some of the hags, so I start by looking up hags in 3e. The sea hag is CR 4 and 1,400 xp, and the green hag is CR 5 and 4,000 xp, so the sea hag is an exact match for CR, size, and type. (Note, you have to take xp with a grain of salt in 2e, and also look at HD, but I'm only using it for a ballpark idea, so we don't have to worry too much about that.) In 5e, sea hag is CR 2, and green hag is CR 3. So we are looking at a CR 2 monster in 5e.

You may also want to look up monsters with a similar concept, even if they differ in CR, size or type. In this case, I want to take a look at dryad, since it's the closest fit, and mayber satyr, since there aren't a lot of fey in 5e. I'm also going to take a look at those high-level eladrin lord things in Mordenkainen's Tome of Foes, since there is a winter one there. In 3.0e the dryad is CR 1, but in 3.5e it is CR 3, so a pretty big boost. The 5e dryad is CR 1, which would probably convert to somewhere between the 3.0 and 3.5 version. We'll that's a bit of a mess. The 2e dryad is only 975 xp. 3e satyr is CR 2-4 (depending on pipes) and 2e satyr is 975 xp. In 5e, our satyr comes in at a pathetic CR 1/2, with no mention of what the optional pipes would do to that. I already know that those super eladrin are CR 10, and there is no point in looking them up yet.

The most accurate 5e conversion would have me making them a CR 2 creature: that would give it the same CR as the sea hag in both editions. Dryad was a lower CR in all previous editions, and with it being CR 1 in 5e, in fits right into place.

But...here's where I'm going to not be as accurate as I could be for my own reasons. I think a lot of the MM manuals in 5e need higher CRs to stack up properly to the monsters from other 5e sources, which tend to have higher CRs relative to MM monsters than they did in previous editions. Ie, they artificially inflated the CR of monsters that came out in later books, which throws off the balance between them. Sometimes monsters that were actually supposed to be weaker in previous editions were made stronger because they came out after the MM and they wanted to make higher CR monsters. All of that to say that I'm going to be personally increasing the power of many MM monsters (including the dryad). And, just because I want yuki-on-na to be less of a pushover, I want them to have a higher CR relative to other monsters than they did even in 3e and 2e. So with that consideration: I'm making my 5e yuki-on-na CR 3. That puts them on par with the green hag currently, and maybe they'll be on par with the sea hag later if I buff them. We'll see.

Figure out what special features you want to convert and add. The 2e and 3e yuki-on-na have a paralyzing gaze (limited to one creature per round), and at will spells that would convert to the 5e spells: disguise self, comprehend languages, and detect thoughts. It also has a 1e spell, know history, which is kind of a 1st level member of the legend lore family. They also have an ability to cause a creature to get lost by touching them. They have an icy touch that deals what would have been good damage in 2e. She's also immune to cold and vulnerable to fire.

I'm not sure what, if anything, I'm going to do with the know history part, but the rest of it will probably convert over fairly easily to 5e.

But am I satisfied? Nope, I want more. My first thoughts are that I'd like her to have some sort of snow-themed misty step kind of ability. My second thought is that I'd like her to be able to conjure up highly localized snow storms (in combat time), and maybe be able to affect weather outside of combat time (unsure of that).

Here is where I'm going to do a quick once over of those other creatures I looked up for comparison to see if there are any ideas for special abilities in there. 3.5e dryads have that minimal fey cold iron damage reduction, which isn't really well represented in 5e fey, but the winter eladrin have fey step, some spells worth glancing at, and a sorrowful presence I might look at. They also share magic resistance with satyrs (who otherwise have nothing of interest). Hags aren't going to be terribly useful here, though Illusory Appearance seems like a good stat-block way to represent the disguise self sort of ability.

What I'm going to figure out right now is how to represent here snow conjuring features. Sleet storm looks like it could work with a bit of refluffing to make it blinding snow rather than sleet. The air elemental has a whirlwind attack that also has some merit. For non-combat blizzards, control weather or a feature based on it is the way to go.

So here's what she should have so far:
Cold Immunity
Paralyzing Gaze
Icy Touch
Lose the Way
Fey Step
Illusory Appearance
Innate Spellcasting: comprehend languages, detect thoughts
Combat snow storm


Maybe Fire Vulnerability
Maybe Magic Resistance
Maybe control weather or similar

Make the features you can. I don't think there is anything there that I can't make before knowing the rest of the stat-block, so I'm going to get to work on them immediately. I'll start with the ones that seem the easiest to figure out, and finish up with the harder ones.

For the paralyzing gaze, the yeti has an extremely similar feature. I'm going to take out the damage and switch it to a Wisdom save for the more mystical element, and this is what I get:

Paralyzing Gaze (Action). The yuki-on-na targets one creature it can see within 30 feet of it. If the target can see the yuki-on-na, the target must succeed on a a DC ??? Wisdom saving throw against this magic or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If the target’s saving throw is successful, or if the effect ends on it, the target is immune to this yuki-on-na’s gaze for 1 hour.

For Fey Step, I want to give it a rider, and I look at the PC eladrin rules for inspiration. I also like the idea that this is easier to use in a snowstorm. The lore says they normally appear in snowstorms, and I want mechanical ways to make that their ideal option.

Winter’s Step (Recharge 5-6). The yuki-on-na dissolves into whirling snow and reforms up to 30 feet away in an unoccupied space it can see. Each creature of its choice that it can see within 5 feet before it teleports takes ??? cold damage.
If the yuki-on-na starts its turn inside a snowstorm, this feature immediately recharges.

Illusory appearance is a straightforward conversion, though I'm not sure I want to leave it as a bonus action to end. I see her dropping it at the start of combat, and she might have other combat things to do with that bonus action. We don't want her to be stuck disguised rather than having the cool reveal, just because it's mechanically disadvantageous to literally give up her disguise! I put in some other end conditions that should cover using any of her supernatural abilities.

Illusory Appearance (Action). The yuki-on-na covers itself and anything it is wearing or carrying with a magical illusion that makes it look like another creature of its general size and humanoid shape. The illusion ends if the yuki-on-na takes a bonus action to end it, makes an attack roll, deals damage, forces a creature to make a saving throw, or if it dies.
The changes wrought by this effect fail to hold up to physical inspection. Otherwise, a creature must take an action to visually inspect the illusion and succeed on a DC 20 Intelligence (Investigation) check to discern that the yuki-on-na is disguised.

For her innate spellcasting, I took some inspiration from dryad and threw in druidcraft. I also limited the frequency of control weather, because I don't want it to be something she can use regularly. They often rely on existing blizzards.

Innate Spellcasting. The yuki-on-na’s innate spellcasting ability is ??? (spell save DC ???). It can innately cast the following spells, requiring no material components:

At-will: druidcraft, comprehend languages, detect thoughts
1/day: confusion (see below)
1/week: control weather

Lose the way is tricky. In both editions it was an automatic effect. It's written in a non-combat sort of way, but seems like it should also have combat effects. I had to put a bit of work into it, but here's what I came up with.

Lose the Way (1/Day). The yuki-on-na touches a creature under the effect of its confusion spell and causes them to become completely unable to find their way anywhere for the next 24 hours. During this time the target’s speed is reduced to 10 feet and it can’t benefit from any bonus to its speed. It automatically fails any ability checks to avoid or recover from getting lost, and cannot even find its way across a field or from one room to another by itself. It can move at its normal speed and be guided by another creature holding its hand or otherwise guiding it by physical contact. If the creature can teleport or travel to other planes, it cannot do so while under this effect.
This effect can be ended early by a remove curse spell.

Icy Touch and Combat Snowstorm are the features that are going to have the biggest effect on her DPR, so we'll postpone those for now and move on to the next part.

Figure out the creature's basic stats. I'm going to figure out most of the other stuff in the statblock here, and I don't anticipate having a lot to slow me down at this point. A few things may need tweaked later.

Ability scores are a part that requires some work. 5e dryads brought over their 3e ability scores exactly, with the exception of Dexterity. 3.0 and 3.5 differed on Dex, but in 5e they had her use barkskin so they gave her a lower Dex to fit the AC they wanted. Hags didn't stick with 3e nearly as much, for the same reason that dryads have different Dex: they needed to adjust stats for the 5e combat math. However, the green hag just got some straight up buffs. Since I'm making my yuki-on-na be a more powerful 5e creature than she was a 3e creature, I also might boost some stats.

Medium fey, chaotic good or chaotic evil
AC 17
(see below)
Speed 30 feet
Str 10 Dex 16 Con 10 Int 15 Wis 16 Cha 19
Damage Vulnerabilities fire
Damage Immunities cold
Skills Stealth +5
Senses darkvision 60 feet, passive perception 13
Languages Common, Spirit Tongue
Challenge 3 (700 XP)


While the monster eladrin just get ridiculously high natural armor to represent their supernatural protective abilities, I'm not sure I like it being conceptually written that way for this delicate creature. Instead I'm going to take a page from cambion and give her this:

Spirit’s Blessing. The yuki-on-na’s armor class includes her Charisma bonus.

To go along with the lore about hiding in the snow, I gave her Stealth (no other skills seemed necessary), and this feature adapted from Wood Elf:

Snowy Veil. The yuki-on-na can attempt to hide even when only lightly obscured by falling snow.

Damage vulnerability is normally to be avoided even if previous edition lore or rules might have given it, but in this case, I actually think she's a prime candidate for fire vulnerability. However, that does weaken her, and I'm going to give her Magic Resistance to help offset it.

Magic Resistance. The yuki-on-na has advantage on saving throws against spells and other magical effects.

You can substitute Sylvan for Spirit Tongue if you want your languages simpler.

As I moved on I realized she didn't have any reaction, and I really, really want her to have a reaction. The obvious choice is to move her WInter's Step to a reaction, but I would rather keep it under her control. A thought finally came to me that letting her cast her 1/day confusion as a reaction would be a great way to make sure it gets used without sacrificing damage for the round. I decided to make the trigger be something that almost certainly will come up unless creative PCs know about it and take steps to fight differently, and seems appropriate. So attacks cause it, but damaging her by other means, such as failed saving throws, don't.

Maiden’s Lament (Reaction). When the yuki-on-na is hit by an attack it casts confusion, using its daily casting of the spell.

At this point, I basically have everything except hit points and her attack/damage dealing features--the stuff that needs to be adjusted to fit her intended CR.

Figure out that math. Now I'm going to make those CR determining features. I can start by just getting her a defensive CR of 3, since I see her as a rather balanced type, not particularly higher in offense or defense. I might have to adjust it later if the offense feels off, but I think that's where I will start.

Determine what features affect the defensive CR determination. I know that Magic Resistance raises her effective AC by 2.

One would think the yeti's chilling gaze (and thus the yuki-on-na's paralyzing gaze) would have an effect on the CR, since taking an opponent out of the fight for a round reduces incoming damage. This is where I have to get creative, because there is a blind spot in the MM on this. If I figure a character will save out of the paralysis on their first or second try, that means paralyzing a creature is probably worth removing a 1.5 rounds of its damage output. Depending on how often you can use this feature over the course of three rounds should determine how much additional effective hp you should consider the monster to have.

In the case of the yeti, who can and should use this feature every round, I calculate it as giving the yeti an effective +25% hp. In the yeti's case, this doesn't move its hp to a different line, and so has no actual effect. Allowing the yuki-on-na to use this feature as part of a multi-attack routine each round makes a lot of sense and will probably be needed for her offensive CR, so we can use the same number here. There are no other features that affect defensive CR.

The yuki-on-na's special features mean for purposes of determining her defensive CR we treat her as having 25% more hit points than she actually has, and treat her AC as if it 2 higher (ie, AC 19).

Set hp for desired defensive CR. So now we just need to determine her hit points to get that CR of 3. With her high effective AC and extra effective hit points, we know we're using a line below CR 3 for hp. They all have an AC of 13 listed, which means we can determine how much her AC shifts that: 19-13 = 6; 6/2= 3 levels higher. If her hp are in the 1/2 column, then that would work. We just need to make sure that (like the yeti) those 25% extra effective hp don't move her to the next row. That means we just need her hit points at 56 or under, which with d8s (for medium size) averaging 4.5 per HD and no Con bonus, means 12d8 gives us 54 hit points, which is an effective hp of 67.5.

Hit points 54 (12d8)

Determine what features affect the offensive CR determination.

Before I continued with this, I had to figure out how to do her snow storm conjuring. I'm getting sort of tired and need to do some other stuff, so I just gave her sleet storm 1/day with a note to fluff it a bit differently, and added it into her "cast as a reaction" spells. There is no particular reason you couldn't have the spellcasting be a bonus action and the Winter's Step a reaction, but I like it better this way for some reason. These spells don't deal damage, which means we'll have to determine how much damage they would deal if they were damaging spells. Using the 2024 DMG guidelines (a bit better than the 2014 ones), a 4th level spell does about 33 damage, and a 2nd level spell does about 17 damage. So this means that she is treated as putting out an additional 50 damage over the course of the encounter, which we need to take account of when determining the damage of her actions and bonus actions.

Her attack bonus and saving throw DCs are going to be based on Charisma so it's +6 attack, and DC 14. I've got a feeling that her damage will rely more on saves than attack rolls, which will mean that we won't have adjust the damage line.

Other than the 50 "effective damage" from those spells, nothing is affecting offensive CR.

However, as I started running numbers, I came up with a problem. There is too much "effective damage" and not enough real damage. Confusion and sleet storm are great, but it doesn't matter how much you mess with your foes if you can't actually do enough damage to win. Granted, you shouldn't use only one monster in 5e. However, almost completely relying on minions and allies to deal damage isn't really good monster design. If I give her a reasonable amount of real damage, then it is going to push her offensive CR up to 4.

Now we figure out how to fix this issue. I could eliminate her Magic Resistance. Or drop her AC by 2 (removing the Spirit's Blessing feature and just giving her natural armor). But a better solution would probably be to take away the ability to cast those spells as reactions, and leave them as something she'd have to commit her action to doing. Hmm...running more numbers, there isn't any way around it. I'm going to have to do something to reduce her defensive CR down to 2. Dropping her hp enough to get her into CR 2 territory with the extra effective 25% hp, would leave her at 36 hp, and I'm not comfortable going that low. If I lower her AC by 1 point, I can keep everything else as-is. So let's drop her 16 Dex down to 15, and her AC to 16. Now her defensive CR is 2, and there is more space to work with for offense. But if I remove the ability to cast spells with anything but an action, she'll be giving up one use of Paralyzing Gaze to cast confusion (sleet storm will be worth less than her attack routine and so it won't be involved in the calculations, but is a situationally useful option), which means that her effective hp are no longer increased by as much. Now it's more like a 15% increase. That would still require her to have less hp than I'd like if we dropped to the CR 1/4 line, so I'm going to leave everything else the same, except I can raise her hp a bit to 58.

Set damage output for desired offensive CR. I'm changing Lose the Way to a bonus action, because otherwise it is never worth using. It is weak enough that it isn't going to have any effect on her CR. Now that that is taken care of and we have an offensive CR 4 to work with, we can figure out how this is going to work. A larger percentage of her damage actually is going to end up being from her Icy Touch attack, so that means we need to use the CR 3 damage line. The maximum damage over the course of three rounds is 78. Subtracting 33 for an opening confusion leaves us with 22.5 damage for each remaining round. The damage from Winter's Step also needs to be included, and with a recharge 5-6 we can assume it isn't going to recharge, so she get's one use in those 3 rounds.

Icy Touch. Melee Spell Attack: +6 to hit, reach 5 ft., one target. Hit: 11 (2d10) cold damage.

Winter’s Step (Recharge 5-6). The yuki-on-na dissolves into whirling snow and reforms up to 30 feet away in an unoccupied space it can see. Each creature of its choice that it can see within 5 feet before it teleports takes 11 (2d10) cold damage.
If the yuki-on-na starts its turn inside a natural snowstorm (including one created by control weather), this feature immediately recharges.

I'm using d10s because the original used those numbers, and there's no reason not to. Multi-target effects are assumed to hit 2 creatures, so Winter's Step does 22 damage in the fight. She uses Icy Touch along with Paralyzing gaze as a multiattack each of the other two turns, dealing a total of 22 more damage. I could have instead had Icy Touch deal 3d10 damage, and Winter's Step only deal 1d10 for exactly the same mathematical results. However, I just don't see her at-will physical attack doing a crazy amount of damage like that. She is very much a finesse monster, designed to make use of multiple features and interactions.

Finish up the rest. At this point, if I weren't converting an existing creature, I'd write up lore to go along with her, but since I already have the lore in two books, I'm not going to reinvent the wheel. The only other thing I can think of is that I'd still really like to give her a reaction, but I don't have the "budget" left for one that affects her CR, since she's already sitting pretty high on CR 3. I can, however, give her a feature that is useful but not useful enough to affect her CR. Oh, and giving her a ranged attack wouldn't go horribly amiss if I can swing it.

Got it. You'll see them in the write up. Note that while I gave her ray of frost for concept, it is only dealing 1d8 damage and can't be used with Paralyzing Gaze, and is therefore an inferior option only to be used as a backup.

yukionna.jpg


You can see some little changes that I made. I improved Snowy Veil and Icy Touch. I changed the language for ending Illusory Appearance so that forcing targets to make saves with detect thoughts doesn't end it, but Paralyzing Gaze does. Instead of the know history thing, I gave her Insight.

I wrote the language up as gender-neutral like the monsters in the 2024 MM in case anyone wants other-gendered yuki-on-na (though I like keeping them with a strong gender-identity).

She is a complicated opponent. If you run into her by herself (not mechanically recommended, but lore-wise, should probably happen sometimes--though the 2e version lists "No. Appearing" as 1-3) and start a fight, she's going to open with confusion. Then, on this round or the next, she's going to use her bonus action to get up into the faces of as many people at once as she can and use Winter's Step to damage them and get out of range. The sooner she uses it the more likely she'll luck out and get a recharge. On subsequent rounds she will use Paralyzing Gaze and then move up and Icy Touch someone. Wind's Escape will help her get away from an attacker that she just slowed down with Icy Touch. She's supposed to be mobile and flitting around the battlefield. She relies on decent AC for her defense.

I just now went back and made her immune to environmental effects and difficult terrain related to cold, snow, and ice, which means she is basically immune to all of the drawbacks of sleet storm and can operate inside it unhindered while others are blind, slow, slipping, and losing their concentration. It's possible that this completely throws off all of my balancing, since it presents an entirely new way for her to fight. It does, however, mean she's casting that instead of casting confusion, and it's probably not any stronger than confusion, even with her immunity to the effects, so we're probably okay (if in doubt, leave out that last sentence of Snowy Veil). It gives her an interesting alternate option for starting a fight, or even more useful, an option for fleeing from a fight.

I also think a fight against 2 or 3 yuki-on-nas would be quite interesting and challenging.

I'm personally a fan of yuki-on-na's. I like how 3e expanded the alignment options from just CE to also CG. You could also open them up to "any Chaotic", but I'm not sure that's needed on the typical alignment line. There is always the possibility of a different alignment than listed anyway. Because I'm a fan of the concept, I put a lot of cool stuff in, rather than going with only a conversion, and I increased the CR one level beyond what a strict conversion should do to it.

(And, there is no way in heck I could have done this without the monster creation rules in the 2014 DMG ;))
 

Attachments

  • yukionna.jpg
    yukionna.jpg
    190.7 KB · Views: 9
  • yukionna.jpg
    yukionna.jpg
    164.4 KB · Views: 8


@Sword of Spirit I think you have done a good job here showing that the guidelines work...but also why WotC may have decided to not include then in a guide aimed at helping new DMs get started.
Absolutely. Unfortunately they seem disinterested in coming up with a better presentation of the math, and would rather just leave future DMs with no information on how to make new monsters. And since they have their internal rules for monster creation, that makes it even sadder. It's not like it's something they don't have--they just don't want to refine the presentation and sell it to us.

Maybe if I actually finish the goal of 5 monsters I'll be able to put together a better presentation of the rules by the end.
 

Absolutely. Unfortunately they seem disinterested in coming up with a better presentation of the math, and would rather just leave future DMs with no information on how to make new monsters. And since they have their internal rules for monster creation, that makes it even sadder. It's not like it's something they don't have--they just don't want to refine the presentation and sell it to us.

Maybe if I actually finish the goal of 5 monsters I'll be able to put together a better presentation of the rules by the end.
Word on the Street is that a Mobster Buider is coming to Beyond, and I would not be even a little surprised if they bring out another take at this system somewhere along the line, like the next Everything book in a couple years.
 

Trending content

Remove ads

Top