Monster design

Gus just posted about trick monsters, focusing on special attack modes (attacks that rust PC equipment, poison, and so forth). While I think attack modes can be a useful device to distinguish monsters, and can add to the puzzle nature of enemies, it is weaknesses and attack patterns that truly add distinctiveness to an enemy. Special attack modes can increase the danger of an opponent, and reward players for learning to avoid the attack (such as fighting poisonous giant spiders only from range), but can also make monsters more of a hazard to be avoided rather than a puzzle to be solved. This is not necessarily a bad thing–I certainly think pure hazard monsters have a place–but there are other opportunities available in monster design as well.

First, let’s review some weaknesses present in classic monsters. The basilisk can be petrified by its own gaze, though few guidelines other than requiring light at least equivalent to a torch are given. The bulette is AC -2 in most places, but only AC 6 under its raised crest and AC 4 at its eyes. Presumably those areas can be targeted using called shots. Chimeras have variable AC based on front, side, and rear. Dragons are vain, covetous, greedy, and vulnerable to flattery. Surprisingly, there seem to be few elemental vulnerabilities. Salamanders, which are fire based monsters, take an extra point of damage per die from cold attacks, and there are a few other cases like that, but, for example, while frost giants are immune to cold, they do not seem to take any extra damage from fire attacks. Many (all?) undead take damage from holy water. Rakshasas are killed instantly by blessed crossbow bolts. Puddings and oozes have a nice collection of reactions to various attack types that are too complicated to list here but have some interesting effects on gameplay. Giant slugs are not actually vulnerable to salt.

Many “vulnerabilities” are actually just the only way to damage a monster that is otherwise immune to attack. Lasting damage can only be dealt to a troll using fire or acid, for example, and wights can only be damaged by silver or enchanted weapons. This penchant for increasing monster danger by making them impervious to everything other than a few carefully chosen attack modes is appropriate for some creatures when easily intuited (ghosts being immune to physical blows, fire elementals being immune to fire, and so forth), but may not be the best approach in all cases.

Attack patterns are rarely seen in traditional D&D monsters, and this is a shame, because they potentially allow players to learn about monsters experientially in addition to via clues and rumors. 4E has a few nods in this direction, though they are more often phrased as capabilities and concerned more with balancing numbers than they are with encoding combat dynamics (the 4E approach to monster weaknesses was more about the four different defenses, which unfortunately are more about monster level than anything else). Giving some attacks a “recharge” limiting its ability to be used sequentially is a nice, usable mechanic, however.

I have been playing a lot of Dark Souls recently (more on that later in the form of a massive upcoming post), which has exceptionally good monster design. So as an exercise, I will stat up the Asylum Demon. Minor spoiler warning here I suppose, though this is only the first boss in the game. It is really part of the tutorial level, so I feel justified in potentially exposing some secrets. Now, this should be a massively punishing encounter if faced head-on, but should be possible to defeat, even for a basically equipped first level party, if approached intelligently. I added some touches of my own to help migrate from the video game to the tabletop context. I chose this monster in particular because it is essentially a physical beast that does not rely in its design on vulnerability to specific energy types or similar things and effectiveness fighting it should depend primarily on tactical decisions. Numerical scale assumes OD&D but would probably work okay in B/X or AD&D as well, with slightly lessened difficulty.

Here is a good video of the fight against the Asylum Demon.

Asylum Demon

Asylum demon gonna step on you (source)

Asylum demon gonna step on you (source)

HD 10, AC as chain (5/14), movement as encumbered human (lumbering walk and awkward flying). Any human not lugging a chest or similar oversized object will be able to outrun the asylum demon.

Asylum demons are horrific, bulbous, brutal demons. They are often guardians unable to range extensively from their post.

Several enemies near: horizontal weapon sweep attack, +10 vs. AC, 1d6 damage, compare one attack roll to all nearby enemies.

A good target at reach: hammer slam 2d6 damage, save (vs. stone?) for half.

No enemies near: fly awkwardly up towards biggest cluster of opponents and attempt to position for good attack next round. Any opponents that do not scatter additionally subject to stomp next round for 1d6 damage, save (vs. stone?) for half.

Weak in the mouth, back of neck, and rear shank. Called shot to the mouth is possible with reach (if adjacent or climbing/grappling) or missile weapons at -4. Accessing the back of the neck requires either jumping from above or climbing first. Successful attack against the mouth or rear shank deals +1d6 damage and to the back of the neck deals +2d6 damage (other additional backstab damage may also apply).

Immune to ranged attacks from human scale missiles such as arrows, bolts, or hurled spears. They “stick it its leathery hide ineffectually.”

Clues: it roars periodically, “exposing pink, fleshy mouth skin.” Anyone behind the demon should notice the “mottled, unprotected rear shank” (though note the demon will never expose this area unless proactively flanked). Consider including balconies or other high vantage points nearby to allow for jump attacks and make sure to mention them when describing the area initially. Asylum demons are huge, lumber brutes and their heavy treads can generally be heard though several walls.

Salvage: asylum demon hide is useful for making leather armor that is particularly protective versus piercing attacks (as plate versus piercing, 1d6 suits worth per demon skin). The weapons they carry are quite fearsome, but may require superhuman strength to wield effectively (yeah, this depends on some other subsystem or ruling that I am not going to get into here).

Is this too much text for a single monster? Perhaps. It is always hard to gauge for yourself how useful a writeup will be to others since, as the author, you already have a good idea in your head of what it is you are going for, but I think this compares favorably with many published monsters, and I think the trigger/action format, with important points emphasized, would be easier to use at the table.

The 2E monstrous manual presented foes as a collection of common game stats (AC, movement, HD, THAC0, etc) along with sections on combat, habitat/society, and ecology. While there are nuggets of useful game info buried within these page-long entries, and some creative world building, for purposes of running encounters it seems like some other categories might be more useful. Triggers for different kinds of attacks, clues to weaknesses, and guidelines for placement, as shown in the asylum demon entry above, are all candidates. Also, fears, hates, and desires. Some such things can often be derived from common knowledge (such as wild animals or carnivores being able to be distracted with rations or livestock), but other details may merit a mention (for example, the wraiths in the Vaults of Pahvelorn will often not molest intruders if they are brought sacrifices to drain). I clued that with remains of previous sacrifices.

All D&D examples in this post were drawn from the 2E Monstrous Manual because it was nearby.

8 thoughts on “Monster design

  1. Jarrett

    Great point about the vulnerabilities of monsters playing such a key role. Player knowledge becomes character knowledge and monsters become puzzles. Two of western civilization’s most iconic monsters are vampires and werewolves — it’s probably no coincidence that these are adversaries with distinct vulnerabilities.

  2. Gus L.

    I’m happy to see you’re giving this monster design issue some thought as well, I like your Asylum Demon and hear where you’re going with special defenses v. special attacks. I am still a bit convinced that special attacks are special defenses, in some manner as they allow a weak creature to become much more terrifying (i.e. a stronger creature) then it’s HP/AC and DMG capacity suggest.

    I believe that the popularity of special attacks in D&D ‘trick’ monsters exists primarily because D&D combat is abstract and hence working out attack patterns is harder and maybe less rewarding. The descriptive burden of explaining the Asylum Demon’s attack pattern in a way that is comprehensible and yet still requires figuring out is a heavy one. In a 3d action/pattern/rpg like Dark Souls there isn’t only the element of learning the enemies tricks (the fun part), there’s the twitch aspect of blocking, dodging and attacking on a really tight time scale. D&D can’t replicate this.

    Second player/GM expectations are a bit player focused in the D&D combat mini-game. Special attacks go after the player directly, meaning they only have to be managed when the monster itself acts (often a much shorter stage of combat then player action), meaning that while resistances are easy enough to handle, complex defensive mechanisms may much less fun as the GM will be taking a much longer combat turn without placing the characters in direct danger. I am having trouble explaining this second rationale.

    Point is that special attacks can be stand ins for defenses. Let’s take a simple monster – a ‘goblin assassin’. The special attack way of making this monster is to say it’s a 1-1HD goblin (attack +0/D6 damage/D6-1 HP) that can jump out and stab characters in the back like a thief. Effectively the goblin now becomes 3HD (attack +4) monster that does 3-18 on it’s first attack, but if detected it’s still a weedy little grot. The other alternative would be to make a 3HD creature with a 3-18 attack that has a weakness for ‘forthright confrontation’, that is if you step to the goblin assassin, in straight on melee it takes double or triple damage and suffers a -4 to attack and reduced damage capacity. These are effectively a very similar monster.

    Now personally I think there is plenty of room for monster special defenses, but they need to be simple to describe, just like attacks. I’d look to the less action focused MMORPGs and 2d/iso brawler bosses for inspiration. The period of obvious invincibility (party must retreat or fight defensively), the attack that slowly charges, and the round of vulnerability where the party may with to launch their best attacks.

    1. Brendan Post author


      Part of the reason that I think Dark Souls is such a good fount of ideas for tabletop games is that the twitch reflex actually plays a relatively minor role in combat success. There is a small, unavoidable part that is dependent upon manual dexterity, but in general the pace is leisurely enough that strategy dominates. I say this as someone who is generally terrible at button coordination (I still can’t reliably do the parry/riposte thing and so rarely rely upon it, though I have the backstab 90% down). Monsters go from oh my god this is impossible how will I ever beat this to consistently defeated once appropriate tactics are discovered, and this is also mostly independent of gear and stats (though poorer numbers gives you less margin for error).

      I think D&D probably can replicate this sort of attack pattern, though admittedly it needs more play testing.

      With your goblin assassin example, where is the clue? How could an intelligent player learn to game that monster? It is possible that clues here have to be at the social level (approach via the back to take the ambushers by surprise, etc) but some systematic way to mitigate the danger seems like it would be a good idea. Otherwise, it is a gamble, not a game. A trade-off between speed and surprise chance? A benefit from active scouting? Successful stealth allows the automatic surprise of ambushing enemies? I don’t know; I have tried a few of these in games that I have run, but I am not super consistent about method here (which means that I guess I should think about it more). Maybe this is overly dogmatic, but I feel like smart play should always be able to, if not entirely eliminate any gamble aspect, at least heavily mitigate it.

      Boss cycles are a good idea, though require care to preserve a sense of naturalism. “Big weapons” that require charge up time or rituals which take several rounds to happen but produce some major change or effect. Another avenue maybe worth pursuing is monsters that have multiple stages.

      1. Gus L.

        I haven’t gotten as far in Dark Souls, but to an extent I think my critique of the abstract D&D battlespace for tactical monster weaknesses applies. Specifically the burden of description placed on the GM. not to say it’s not a good place to start with monster design, I to find the monsters in Dark Souls well designed.

        The thing about the goblin assassin that would provide a clue (and I think one is necessary) is to indicate the presence of assassinating goblins earlier in the adventure. Since it’s an ambusher the clue can’t be intrinsic to the encounter Good scouting would be the obvious solution, a murdered backstab victim or even a descriptive clan name might also suffice. Environmental clues might be helpful, like an entrance corridor covered in ragged tapestries – which should make any party nervious.

        Yeah I find this whole description thing pretty interesting.

      2. Pearce Shea

        You could cut out a lot of the text and the result is something that’d be pretty close to a major encounter written by Gygax or the like: the Demon has basically three “moves” (attack, attack and move to attack), an immunity that is really easy to discern (also easy to telegraph if you wanted to – could be studded with arrows) and some weaknesses.

        I really don’t think there is a “better” technique here (telegraphing pre-combat, signaling in combat), though I’ll note that telegraphing seems preferable in any scenario where the actual encounter features a purely mechanically governed chance of instagib (poison, petrification, etc).

        I have a lot more to say about Dark Souls and design in this specific context but I won’t clutter up the comments here.

      3. Brendan Post author


        I would say that the best designed monsters will come with rumors, clues, and tells. The more ways to learn about setting elements through experiencing the setting itself, the better.

        Anything about Dark Souls and monster design doesn’t sound like clutter to me, but I wait with interest for your now-promised post in any case.

  3. James Young

    Having salvage info is super cool.
    Having clues to it weaknesses are also super cool.

    I am doing this for any big boss style monsters I make in future, it rules.


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