The Limit of Challenge as Level Approaches Infiinity


One thing that has always intrigued me about D&D is that there are certain monsters which are a challenge at low levels, which very quickly cease to be a challenge so that within only a few levels they aren't even a nuisance and consume virtually no resources to overcome. But, other monsters - no more a challenge than there peers to a low level foe - manage to hang on as challenges even as the party grows in level so that you might find yourself fighting the same monsters under increasingly difficult circumstances for most of your career.

As a DM I find myself relying pretty heavily on these monsters.

I'm not talking about monsters that can simply be scaled up in power as any monster can be scaled up - which third edition showed explicitly and even 1st edition implied. I'm talking about monsters which while retaining the same stats remain an non-zero challenge over twelve or more levels and still might in numbers threaten even a powerful character.

I'm likewise not talking about Tucker's Kobolds or similar scenarios where the monster is merely the trigger for a sentient trap. Tucker's Kobolds typically involve the DM abusing the rules, bending the rules, preferentially ruling in favor of monsters in circumstances where things would never work if the PC's tried them, and simply by making the monsters stats irrelevant in the encounter. Obviously, the monster is irrelevant in the case and the real challenge is a combination the devious trap and getting the DM to admit that you killed his pet monsters.

For example, the zombie is not a monster of this sort. At low levels a gang of zombies might represent a considerable challenge to a group of players, but within only a few levels these lumbering, landbound, melee only, stupid, turnable creatures with low BAB and no special attacks are rendered irrelevant unless the DM turns the environment into a trap or advances the zombie to greater power - say an ogre zombie.

The same is true of most humanoid monsters that rely on weapons to attack. Gnolls in particular seem to gain and then lose their fearsomeness quickly. The same is also true of virtually all animals.

If we look at why this is true, certain traits stand out.

a) The monster lacks a counter to an ability which the PC's will have either shortly after the monster is encountered or even by the time the PC's encounter it. The most obvious example is Flight, which allows a party with this ability to gain an absolute advantage over landbound monsters without ranged attacks whenever it can be succesfully deployed. This forces the DM to only use such a monster in a carefully confined space, else it won't live up to its CR.
b) The monster has a low 'to hit' score not only absolutely but even for monsters of its class, usually as a result of roughly human strength, and no way of coping with high AC. AC has an interesting property. As your AC increases linearly, your expected damage decreases exponentionally. A monster that hits you 15% of the time, does only 1/3rd as much damage if your AC goes up by two. Monsters of this sort might be a threat at level 1, still a nuisance at level 3, only to cease to be a threat even in twenty or forty times their original number by level 5. Skeletons are monsters of this sort, as are most low HD humanoids with roughly human characteristics (including humans!). Such monsters only stay relevant by being granted massive advantages in terrain and tactical position, and refusing to give open battle. Orcs do slightly better with their high strength scores, but they two soon lose relevance. Meanwhile ogres with their high strength and reach might remain at least somewhat relavant for 6-8 levels after they are first encountered.
c) Not undead, or undead with signficant resistance to turning. Once a party has twice the HD of an undead creature, it's usually reduced to insignificance. Many low HD undead qualify, though minimal bolstering from the environment (unhallow for example) can usually deal with this problem without elaborate environment considerations.

Some monsters do exceptionally well and these are the ones which have what I call 'level independent abilities'. Some examples include:

a) Incorporeal: Incorporeal creatures ignore armor and have a 50% chance of ignoring most attacks. This makes it incredibly difficult to get sufficient AC to make their attacks irrelevant, and gives them protection that almost always negates at least some attacks regardless of how high your attack bonus is or how difficult your saving throws are.
b) Touch Attacks Generally: Any touch attack is good.
c) Breath Weapons: Most breath weapons are of the 'save or half damage' variaty, which means they typically remain relavant to all but Rogues regardless of how easy the saving throw is.
d) Certain spells: Spells that are 'save partial' usually have some effect regardless of how good the opponents saves are. Better yet, some spells like magic missile offer no save, and so are exceptionally difficult to defend against. A monster that has the ability to cast magic missile 3/day is relevant for three rounds almost regardless of the parties level.
e) At least minimal defensive suite: Monsters that have a combination of flight, ranged attacks, and the ability to detect invisible creatures are able to counter most of the battlefield control and evasion that a party might try. Additional abilities like spring attack, combat reflexes, relatively high attack bonus for its CR, DR/-, immunities, area attacks, improved grab, high movement rate, and some sort of battlefield control add to and enhance the minimum package or help compensate for some deficiency in it. These abilties are often found in anything intended to have high CR and well designed, but there presence in a low CR monster indicates a monster that has a real life expectancy.
f) Ability drain: Attacks that effect relatively static ability scores as opposed to hit points remain relevant for longer periods.

Some well known monsters that meet these standards in whole or in part are:

Shadow (without cleric)
Wraith (without cleric)
Hell Hound
Hellwasp Swarm (or swarms generally)
Huge Air Elemental
Fire Giant

So, what about it? Have I missed any monsters under 12 CR whose abilities give them great endurance as a monster even as the party climbs in level, particularly those that might be hiding in obscure 3rd edition tomes?

What about earlier editions? I can make similar lists for 1st edition, but I'll leave that excercise to the interested reader for now.
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i'd say that the Wight also retains some of its charm.. especially if their is no cleric in the party.

In the game i play as a player, my party came up recently before a few Wights by the side of a powerful evil cleric. We are level 11 now... Believe me, trying not to get touched by the Wights in the contained room we where fighting... was not easy.

hmm... what about the Gorgon?... i'm under the impression that it can keep a party busy up until level 15 or


First Post
Monsters are somewhat subject to the same problems as PC classes. That is, (su), (ex), SLAs are valuable in a way similar to full spellcasting classes are, especially at higher levels, and melee brutes simply lose the novelty of being able to break stuff, which the spellcasting classes eventually gain a superior method doing in their own right.


How do you feel about annoyances like Rust Monsters, Gelatinous Cubes and Mimics?

Even at low levels, Gelatinous Cubes require the DM manipulate the terrain in their favor in order for them to represent much of a challenge. In effect, they are a sentient trap. If you blunder into one, they are quite a threat, but with their slow movement rate and limited tactical options most parties will dispatch them without expending any significant reasources. I don't favor them.

Mimics are typical of grapplers in that they can be quite a threat if stumpled on, and like any good grappler they have a reasonably good mechanism for closing with PC's or getting PC's to close with them (in this case), but they too just have far too limited of options and mobility. Mimics are rarely going to seriously challenge a party even at party level = CR, and within a few levels of when they can be first encountered they'll represent even less. They are mostly a sentient trap. The only good thing that can be said about them is that they work better in teams than they do solo as thier grapple and adhesion powers can serve as good synergistic battlefield control, but I've very rarely seen them deployed that way.

Rust Monsters are a good deal more dangerous than either of the other two because they have good ground mobility, a level independent power in a touch attack, and an additional almost level independent power in the ability to rust any metal object absolutely. However, the lack of flight or ranged attack cripples them in the long run, and they can only be a real threat to a part of level >> CR if they are in a highly confined space. If you want to use these then, I suggest having the party face them when they are on their hands and knees in a lengthy maze of crawlspaces. However, it should be noted that this creature is almost entirely geared to encounters where party level < CR, because as level increases the gear becomes harder and harder to replace. Losing your masterwork sword and chaimmail at 2nd level doesn't gimp your fighter compared to his wizard companion; the equipment will be readily replaced and you are still the rock of the party. Losing his sword and armor at 15th level will probably render the fighter useless at a time when he's already starting to feel highly overshadowed by his spell-caster friends in every respect. As such, you need to consider the use of this highly gamist monster in a highly gamist way, and make sure that if the worst does happen you've already preplaced oppurtunities for some credible replacements for lost gear later in the adventure.

One thing this should suggest to you is that not all monsters advance evenly. Some monsters don't gain near as much CR as advancing their HD would suggest, and some monsters gain HUGE amounts of effective CR for a relatively small increase in HD. If the monster is of the sort where the limit of challenge as level approaches infinity very rapidly converges to zero, then bulking up the monster with extra HD doesn't accomplish that much. To truly advance these monsters in a way that makes them greater challenges, you have to fix their core issues. A gelatinous cube doesn't gain nearly as much from extra HD and extra size as it gains from moving faster. If you want a truly monstrous gelatinous cube, up its movement rate to something faster than the average PC and give it the ability to levitate and spit small copies of itself as ranged attacks. These sort of things would help increase the challenge far more than 24 HD, although of course doing both is even better. Just be careful that you don't create monsters that are so well balanced that no strategy serves better than a straight up damage race (unless perhaps the climatic BBEG of a lengthy adventure arc when you are trying to avoid anti-climax).


Monsters are somewhat subject to the same problems as PC classes. That is, (su), (ex), SLAs are valuable in a way similar to full spellcasting classes are, especially at higher levels, and melee brutes simply lose the novelty of being able to break stuff, which the spellcasting classes eventually gain a superior method doing in their own right.

I think this is party true. It's quite possible to create highly challenging melee brute monsters, but typically melee brutes are created to such a simple one dimensional template by the monster designer that they have some glaring Achilles heel (like the Tarrasques inability to deal with flying attackers) and simply go down hard to superior strategy especially when the DM hasn't considered the Achilles heel when designing the environment the monster will be encountered in. Nothing so garuantees the frustration of a novice DM as imagining the players playing to the strengths of his monsters thereby producing epic and difficult challenges. Instead, the DM should imagine the PC's playing to the monsters weakness and try to stay one step ahead of the players. You are outnumbered, so you won't always do it, but you'll avoid frustration and the temptation to cheat in the favor of the monsters because they are dying more quickly than you'd desired.


a) except against ghost touch and similar abilities.

b) except against wilders.

c) or monks and at least one other off the top of my head.


excellent points in all. i like the questions you pose.

concerning the cube... there is a simple way to up the movement rate as you suggest. give it the half or full fiendish/celestial template, or something similar. this boosts the int to a minimum of 3, and allows it to take class levels. monk or barbarian or fast-move acf ranger anyone?

i'm not thinking of any monsters off the top of my head that meet your criteria without tending towards situational specific types. except ghosts, perhaps? la +5, and cr+2 of base creature.


The Aoa Sphere might fall under this category.

Mass disenchanting all of your magic items and reflective spell resistance are among it's more interesting abilities. And if enough damage is involved, it splits. =)


The Aoa Sphere might fall under this category.

Aoa falls into the category of monsters that can be usefully advanced by increasing their HD. The monster is a serious threat to spellcasters, but lacks a physical attack that is damaging enough to be much of a threat to non-spellcasters. Assuming you were to first encounter a droplet around 3rd level, the same drop will cease to be much of a threat right around the time we'd expect it to (say 11th level). That's pretty darn good for a CR 3 monster, but without a touch attach or some other sort of nearly level invariant threat it just doesn't quite make it in to the category.

Replace that slam attack with a ranged touch attack, and now we are talking.

The Sphere is not a true advanced version of the Droplet, and at CR 15 is an example of something which has been designed to be relevant at high levels and thus which we'd expect to be effective in to the lower epic (at least). So it's not really in the same category as the low CR creatures I've mentioned so far.

Epic Threats

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