D&D 5E CR and Proficiency

[ProgBard]

According to the monster-building rules, the proficiency bonus for a monster or NPC is based on its challenge rating. As I read it, this number becomes something that you only finalize after doing all the rest of the calculations for CR.

So, all you monster and (especially) NPC designers, how closely do you feel you have to adhere to this? Do you follow the guidelines as written, or set proficiency independently - maybe even as one factor that determines CR rather than is dependent on it?

I find myself tempted to more or less decouple them myself. I'm working on a set of generic-ish NPCs to expand the list in the MM, especially to represent NPC versions of PC-like characters. I realize that characters with class levels are supposed to be "special," but - given that determining CR is almost entirely dependent on 1) how badly something can hurt you, and 2) how hard it is to kill - relegating all humanoid characters who aren't combat monsters or fireball-slingers to the low end of the proficiency scale seems dumb and doesn't model story very well. It feels silly that the loremaster bard the PCs might go to for knowledge on some obscure bit of arcana needs like a zillion hit dice just to get bumped out of the same +2 that every neophyte adventurer gets; OTOH, it feels very much like RAW, and likely RAI, means exactly that, and I suppose it may well be for some very good reason that I have not the arithmetics to savvy.

Arguments? Agreements? Advice? Answers?

 

[MostlyDm]

Nah, your plan is fine. The only reason for the stated system of determining proficiency is to avoid every high HD bag of HP having huge save DCs and attack bonuses.

The system for creating NPCs and monsters is much more ad hoc than your fearing, I think. If logic and story dictate the old Sage has +12 to Nature checks, give him +12 to nature checks. Even if logic also dictates he ought to have 12 HP.

Nothing will be ruined by it. And honestly your world will probably feel more real than trying to slavishly follow the guidelines.

 

[Dausuul]

This hits on one of my pet peeves about 5E's monster guidelines - the circular logic in CR calculations. Proficiency bonus is based on CR, but in order to compute CR, you need to know the monster's attack bonus, which is based on its proficiency bonus!

I'd be inclined to make proficiency bonus an arbitrary value: You just decide what you want it to be, and that's what it is.

 

[Sacrosanct]

The best guidelines for monster design I've found regardless of edition is, "Get familiar with the rules and monsters, and create one that feels right for what you want."

Otherwise, they just feel forced and flawed. I.e., I never follow the guidelines.

 

[ProgBard]

[MENTION=6788973]MostlyDm[/MENTION]: Yeah, that was my gut feeling too. It doesn't feel like it breaks anything, but I am notoriously lousy at intuiting the sort of thing people seem to mean when they talk about "balance."
[MENTION=58197]Dausuul[/MENTION]: That always felt off to me too - as written, it forces you to estimate and then revise. I mean, once you go through it a couple of times, you can kinda squint and guess right, but it's an odd way of doing it, especially when that number governs to-hit AND any save DCs that get factored in to the CR equation.

 

[Dausuul]

@MostlyDm: Yeah, that was my gut feeling too. It doesn't feel like it breaks anything, but I am notoriously lousy at intuiting the sort of thing people seem to mean when they talk about "balance."

It should be fine. All of the channels through which proficiency bonus affects a monster's combat performance (save DCs, attack bonuses) are also affected by ability scores, and the monster designer can set the ability scores to any value s/he likes.

Suppose you have a monster with Strength 14, proficiency bonus +2, and an attack whose base damage is 2d6. The monster has +4 to hit and deals an average of 9 damage (2d6+2) per hit.

Now, let's say you bump the monster's Strength to 18 and scale down the damage dice to 2d4. Both of these changes are totally legit, right? Damage dice and ability scores are both at the monster creator's discretion. So now you've got a monster with +6 to hit, that deals an average of 9 damage (2d4+4) per hit.

But what if, instead of messing with Strength and damage dice, you just bumped the monster's proficiency bonus to +4? Now you've got a monster with +6 to hit, that deals an average of 9 damage per hit. It's functionally identical to the "18 Strength, smaller damage dice" version*. So, changing the proficiency bonus won't break the system, since the end result is the same as if you'd only changed the dials you're expected to.

[SIZE=-2]*Okay, not strictly identical. The monster with a boosted proficiency bonus will deal a bit more damage on a critical hit, and will do less well on Strength saves and grapple checks, and of course it will have better results on proficient skills. However, these differences are trivial from a combat perspective and don't feed into CR.[/SIZE]

 

[ProgBard]

Seeing those calculations laid out together kinda underlines for me what a blunt instrument CR is after all. Which, it really has to be, I think. Because all those spells and skills and special abilities that don't factor into it really can affect how an encounter goes. But there's no way of calculating that with any exactitude without... well, a whole lot more complexity than I have any patience for, I'll tell you that.

 

[NotActuallyTim]

I think the circular logic bit is intentional. It really forces monster builders to run through everything more than once, which helps undercut assumptions about the monster being built.

 

[Li Shenron]

According to the monster-building rules, the proficiency bonus for a monster or NPC is based on its challenge rating. As I read it, this number becomes something that you only finalize after doing all the rest of the calculations for CR.

So, all you monster and (especially) NPC designers, how closely do you feel you have to adhere to this? Do you follow the guidelines as written, or set proficiency independently - maybe even as one factor that determines CR rather than is dependent on it?

Considering these:

- monsters proficiencies that matters are mostly only Perception and Stealth
- proficiency bonus is up to only +6 for CR<=20
- the monster's ability score counts about as much as the prof bonus
- you are probably only going to roll ONE perception and/or ONE stealth check for this monster

my conclusion is that it's not worth to waste time following the guidelines.

 

[S'mon]

The system as written is broken because of the circularity - Prof bonus affects CR which determines Prof bonus which affects CR which....

Best thing is to set Prof Bonus first, so you know what the attack bonus & spellcaster save DC is, then calculate CR at the end. That way you can have experienced, skilled, lower CR foes, and big clumsy high CR low Prof foes as well - the system generally defaults to the latter.