creating compelling monsters

[sokol815]

I am working on my roguelike strife. And find myself preparing to code a more intelligent ai than my current find player, bump player routine.

monsters are responsible for a large portion of the enjoyment one gets out of a roguelike. What features make those monsters contribute most to the gameplay experience?

Some thoughts that I have gathered from around the forum and a few of my own:

• monsters wield all items the npc can wield (what if a monster picked up an amulet of life-saving, then came back to life after you killed them!?)
• monsters have abilities that make some challenging and others interesting (ratling duelists in ADOM, anyone? - side note, that is a great example, positive and negative effects can come from that interaction.)
• monsters use their abilities intelligently and to great effect against the pc
• some monsters represent a need to tactically think about your choices for how and when to defeat them. E.g. explosion on death, gathering more strength each turn, splitting gelatinous cubes, vampire weak during the day
• monsters that trick the pc (maybe only the first time, but oh man, the feeling of being tricked... ) e.g. the classic mimic
• monsters should not all feel 'samey'/like cookie cutter monsters
• some monsters are just pc fodder

I'm curious to know what other thoughts and experiences you forum members have had in designing monsters that add greatly to your games, or even encounters you have had in other games.

[Bear]

I think it's important to make different kinds of monsters act differently.

Some of them should just rush and bump, as you say.  Others should have some unusual pathfinding behavior that the player can learn and anticipate their movements.  -- eg, hasn't seen them in a while but knows he level map so can guess where they probably are and how many more turns he has to do something before they show up. 

Some of them should deliberately hide items and barricade themselves into some kind of strong room.  Some should flee the player on sight.  After all, as far as they're concerned the player is a murdering thief. 

Some monsters should fight each other - so the player may be able to lead a bunch of Vampires into a bunch of Warlocks, then deal with a few survivors and start sorting the loot.

Some should be neutral until provoked.  Maybe you provoke them when you pick up something that's in the room with them, or maybe they don't provoke until you actually attack them.

Occasionally, maybe a member of a usually-hostile race, when cornered, might try to cut a deal -- something like "Don't Kill Me!  I'll tell you whatever you want to know!" and then the player gets part of his monster knowledge and map filled in, and maybe learns what some of the important monsters on the next couple of levels are in advance.

You could consider even monsters as sources of overheard gossip -- when the player is around a corner being stealthy, and a couple of Orc Guards are talking shop, he might learn what they're guarding and decide whether it's worth it to take them on.

[mushroom patch]

I think it's important for monsters to act in concert with each other, something I don't think I've really seen in roguelikes, except to the extent that there's a natural synergy to a mob of monsters all trying to approach and surround you or pelt you with arrows and breath weapons at a distance.

Groups of monsters that play off each other are great even if they individually have fairly simple behavior. Monsters that follow you at a distance but hide until you're being attacked frontally or wait for you to retreat into them would be an example. Or set traps for you to retreat into. Mixed forces with meat shield type monsters and spell casters or archers.

Coordinated teams of monsters are also good. Pack hunting behaviors, pincer attacks, and so on. Monsters with henchmen, pets, or familiars. Crawl does a little of this with its uniques.

In my opinion, you're probably better off designing interesting, general relationships between monsters than actually introducing new monsters, because the possible combinations the relationships can introduce will increase the diversity of monster encounters far more than a new type of dragon will (or even a smarter dragon will).

[Zireael]

I like the "don't kill me! I'll tell you stuff!" and gossip ideas. Baldur's Gate and Neverwinter Nights pulled off the first one in quite a few places, and Deus Ex 1 was the game where I saw gossiping enemies done the best.

[Hi]

A compelling monster is one you can tell stories about.  It has desires and perceptions and gets angry or afraid.  One of the cheapest ways to make a monster more compelling is to have it declare what it is perceiving or what it wants.  for example when an enemy humanoid notices you it could say something like "you're not Fred" or "thief!" or so on.  You don't even have to make the monsters take any action,  simply stating a desire is often enough.  A dragon can say "I smell gold" a guard can mutter to himself "I'd rather be having a nice drink".  As long as they don't get too repetitive this makes it feel like the monsters experience the world and are not just mindless automata.





Random connection but, I have heard that octopuses grew big brains because they have so many enemies that no one tactic works against all of them.  I believe that one of the things that makes a monster compelling is that it takes different tactics to deal with it.

Some Octopus inspired tactics

• Disguising yourself as a dangerous creature such as an orc (perhaps by wearing orcish armor) to scare away weaker critters and allow you to cross open areas more safely
  Decoys to distract opponents so you can run in the opposite direction
  Holding absolutely still so that large predators lose interest.
  Walking without rhythm so sand worms don't detect you.

[Wisp412]

I suggest having enemies that will attack other enemies in general. Its quite immersion breaking when a mindless hoard of splitting worms ignores everything but the player. Surely stimulating a worm nest. locking the door, and luring enemies through it (or as an escape route) would make strategic sense.

Or perhaps having a strong unique that will hunt down other monsters. This potentially steals player XP (which they hate, but usually has little impact), and allows players to fight them while they attack something else.

[DWRoelands]

I've built my game with the idea of monsters being able to do just about anything that a player can do (monsters and players both derive from a base "creature" class).  This allows me to have htem pick up weapons, choose targets, and so on.

[wire_hall_medic]

I've had monsters talk to each other, to good effect.  When a monster sees the player, he alerts all of his allies that he can see.  In open areas, this pulls a group from just outside of visual range.  In enclosed spaces, the player usually stands at a doorway; if there's enough connectivity (there usually is) the monsters start coming from behind.

What I'm working on now is monsters who interact with the environment.  Being able to leap short chasms, break weak walls (or even strong ones, for very strong monsters), intelligently take cover, use corpses.

[Trystan]

I've had monsters talk to each other, to good effect.

I been thinking about this and it seems interesting and fairly easy to implement once you have some basic ai effects like fleeing, targeting, and helping allies. Alerting others is a good start but what if powerful or intelligent creatures could say things to affect the morale of nearby monsters ("It's no use, he has heavy armor!" to increase the chance of monsters fleeing or "Looks like she's running low on mana!" to make monsters less likely to flee) or change their tactics ("Use ranged attacks!" or "Support me, I'm going in!")? So a pack of orcs would be troublesome but a pack of orcs with an Orc Commander who shouts intelligent hints at allies would be much more troublesome because the entire group would be smarter.

[LindaJeanne]

I've had monsters talk to each other, to good effect.

I been thinking about this and it seems interesting and fairly easy to implement once you have some basic ai effects like fleeing, targeting, and helping allies. Alerting others is a good start but what if powerful or intelligent creatures could say things to affect the morale of nearby monsters ("It's no use, he has heavy armor!" to increase the chance of monsters fleeing or "Looks like she's running low on mana!" to make monsters less likely to flee) or change their tactics ("Use ranged attacks!" or "Support me, I'm going in!")? So a pack of orcs would be troublesome but a pack of orcs with an Orc Commander who shouts intelligent hints at allies would be much more troublesome because the entire group would be smarter.

I really like this idea. The game I've been working on, I've been looking at ways of making the creatures behave in more complex ways, including their interactions with each other -- I think I may have to steel this idea .

The AI system I'm designing right now chooses creature actions in two parts -- first, a "goal" is chosen (go get that food, get out of here there's too much danger, need to defend my territory from that intruder, I need to get that cool axe!....) based on what items and creatures (including the player) are in range, and the priorities for the particular creature. Then the steps needed to reach that goal are set, including the pathing.

Nothing groundbreaking, but this is my first RL.

[Pickledtezcat]

Have you ever considered the ecology of the dungeon?

Google it and you'll find a whole bunch of articles for and against the idea.
For a roguelike I'm not suggesting that you have to create a food pyramid and calculate biomass or anything, but it can be cool to think about the various roles in an ecosystem which aren't filled by apex predators.

1. Plants. The bottom rung of a food chain is the plants, they get energy from the sun and disseminate it through the rest of the chain.
In a dungeon there's no sun, so we might look at other ways of absorbing energy. Mold and slimes, moss, jellies can grow underground. They don't have to be active, just passive sources of food for your wandering monsters. It gives your monsters something to do while the player isn't there too.

2. Herbivores. Sheep eat grass and wolves eat sheep. Sheep aren't aggressive, they don't attack on sight, but some herbivores can be dangerous if threatened, like a triceratops or a poisonous frog, they usually have some kind of defensive ability. How about some monsters like this? They won't attack the player unless he attacks them. Other monsters might spend their time hunting these monsters too.

3. Scavengers. There's lots of junk in a dungeon; bones, decayed flesh, metal. And there's usually a scavenger who eats it. How about a rust monster who goes around eating item drops? He won't attack you, but he might eat your gear if you leave it laying around.

So as an example:

In the dungeon a kind of mold grows which feasts on the magical energy coming from a great artifact on the lowest level. These molds are a tile feature, they can be moved through, but set of a poison effect (from their spores) if you step on them. They also have a small chance of growing in to an adjacent square each turn.
Giant centipedes eat this mold. They only eat the mold and won't attack the player unless threatened. If a giant centipede moves in to a square containing mold the mold will be eaten. Giant centipedes always move towards the nearest mold and eat it unless they are enraged in which case they move towards the nearest threat, just like a common monster.

Now you have an interesting game mechanic. If you kill the giant centipedes, perhaps for XP, or for their blood (which can make a potion of poison), the mold will begin to grow. Eventually it might begin to take up the whole level. You could keep track of the number of giant centipedes in the game and if it falls below a certain amount you could start including more mold squares in your random level generation routine further down in your dungeon.

Now you can introduce the following behavior in to your AI (while they are not attacking the player):
Giant Lizards >>attack on sight>> Giant rats >>attack on sight>>Giant Centipedes>>attack on sight>> magic mold.
Though remember to include fewer predators than prey or soon your dungeon will have only predators in it.

[Zireael]

Pickledtezcat, I like the idea.