Creating Creatures & Building Beasts

How to make monsters for your world

How to create a creature for your TTRPG

Writing a creature is a form of setting creation. Each creature you add to your game forms a new element of the setting in the players’ minds.

image by Daniel Locke

The ecology approach

To create creatures, monsters, or just plain weird stuff in your world, think about the space you’re creating. What is the ecosystem? What would feed on the resources there? What would feed on those things? What would the Apex predator be? And what would feed on the Apex predator’s carcass once they die? Thinking about these structures can give interesting ideas, and ways to reinforce a setting.

The inspiration approach

Sometimes you just have a great idea for something that just fits. Always roll with a great idea. They might be the basis for a whole new scenario within your game.

The reskin approach

Probably my favourite approach is to take a creature from mythology, another setting or genre, and think about how they would work in your setting. For ECO MOFOS!! I took the idea of the classic Zombie, and thought- what would this be in a technologically-tinged weird future? I was thinking a lot about Elon’s obsession with implanting chips in people’s brains, and the horrors of AI, and came up with this:

AI Rotting Body

6 HP, 12 STR 6 DEX, 3 WIL, rusty weapon (d8), in Unit of 6d6

• Slow, mindless disintegrating corpses. Controlled by a central Artificial Intelligence beyond death through a brain implant, acting as strategic hordes.

• Attacks anything that comes nearby. Groups will act to cut off exits.

• Cannot be affected by anything that targets the mind. Will collapse if the link to the central server’s severed.

Units are my reskin of Into the Odd’s Detachments - Large groups of similar combatants fighting together, or single huge threats, are treated as a single Unit. When a Unit takes Critical Damage, it is routed or significantly weakened. When it reaches 0 STR, it is destroyed.

• Attacks against Units by individuals are Impaired, except for attacks with the Blast effect.

• Attacks against individuals by Units are Enhanced and deal Blast Damage.

Creating Creatures for ECO MOFOS!!

Here’s a procedure to make new creatures for the ECO MOFOS!! setting:

Roll once on each of these tables to construct a new form. If you have an idea that’s better than your roll, run with that. This is a dice drop, so you can just roll one of every D&D die to get an instant creature. Then I’ll lay out some guidelines to stat it appropriately.

What’s the theme?! Roll d4

1. Hyper evolved - Creatures reformed by Essence, larger, stranger, with exaggerated properties, nature reimagined

2. Degraded - Creatures warped by a harsh environment or as biological weapons. Weird, wired and terrifying.

3. Solar tech - Repurposed and recycled technology, archaic, wind powered, solar powered, clockwork, wood, burnished steel

4. Future Tech - Corpo hi technology, nanobots, drones, mecha, white ceramic and chrome

What is this thing?! Roll d6

1. Droids - some form of construct, from Walking Teapot to Sentient Missile

2. Faction- A human group identity. Maybe they have a particular role or a particular Adaptation

3. Stalking Beasts- Creatures that will follow the party, keen to glean items, information or eat them for supper.

4. Crawlers - semi-sentient creatures that rely on instinct for their actions - Creeping thorny vines, large rats or weird Ooze.

5. Great Beast - an Apex predator. Something large that hunts, or is a large threat.

6. Denizen - Huge monstrous form, should inspire awe and probably fear. Often a Unit. Can be one large thing, or a hoard of smaller creatures.

What’s its general disposition?! d8

1. Vast intelligence

2. Cunning

3. Rabid

4. Ravenous

5. Instinctual

6. Protective

7. Inquisitive

8. Friendly

Whassit look like?! d10

1. Flesh

2. Fur

3. Scales

4. Metal

5. Feathers

6. Insectoid

7. Cloud

8. Plant

9. Rotting

10. Humanoid

What’s a funky detail?! d12

1. Multiple eyes

2. Tentacles

3. Antennae

4. Translucent

5. Iridescent

6. Pure Black

7. Pure white

8. Brightly coloured

9. Camouflaged

10. Strange voice

11. Weird smell

12. Gives off heat

How’s it defend itself?! Roll second time for critical Damage d20

1. Slash

2. Crush

3. Pierce

4. Bite

5. Sting

6. Shoot

7. Punch

8. Kick

9. Touch

10. Stab

11. Shield

12. Teleport

13. Infect

14. Freeze

15. Burn

16. Fire

17. Snipe

18. Emit

19. Blast of Gas

20. Blast of Fire

Name then Stat up your creature

Once you’ve collated your results, think about what kind of creature they might be. Try to give e them a simple descriptive name, one that will be useful for the GM so that they can explain this creature to their table. They may have a different name to some characters within the game itself.

Then think about how this creature’s stats might echo or reinforce their form and how they act in the world.

Creature Stat Block Format

? HP, ? Armour, ?? STR, ?? DEX, ?? WIL, Attack (d?, special items, qualities)

• A rich description of what the creature looks like, how it lives, maybe even how it sounds or smells.

• A weird detail or idea that makes this creature unique.

• List a special effect or consequence of Critical Damage.

Hurt Protection

A creature’s ability to avoid danger, whether through toughness, speed, or skill. Give average creatures 3 HP, rugged ones 6 HP, and major threats 10 or higher. If it is huge, like an armoured truck, mecha or kaiju, make them a Unit.

Armour

For some creatures this represents their hide, shell or scales; for others, it could be armour that they wear or the steel they’re made from. If a creature is able to withstand an attack without moving, raise this number.

Ability Score

3 is terrible, 6 is weak, 10 is average, 14 is significant, and 18 is extraordinary.

Strength

Tracks overall health, physical power, and resistance to poisons.

Dexterity

Start at 10 and if the creature is quick, agile, or nimble, increase the number. If it is slow-witted or ponderous lower the number.

Willpower

Determines a creature’s ability to withstand the influence of another, their determination to continue in the face of adversity as well as their influence over others. Also indicates their natural defence in magical or spiritual stuff.

Attacks

Typically a thing (e.g. blade or gun) or a part of the creature (e.g. laser eyes or self-destruct mechanism).

Abilities

A unique action or power the creature can utilise both in and out of combat.

• If an ability can be meaningfully avoided or defended against through traditional means, it is an Attack and interacts with HP.

• If an ability cannot be meaningfully avoided or defended against through traditional means, it is an Ability.

• If an ability only affects a single PC, it should generally have an immediate effect with no chance to Save in that round (possibly not at all).

• If an ability is capable of affecting a group of PCs, it should generally call for an immediate Save.

Example

I rolled all the dice and got:

Hyper evolved, Protective, Faction, Feathers, Strange Voice, Attack: Crush (Critical Damage: SNIPE).

Now, I see this as a faction of bird people who talk in squarks, but a language that can be interpreted. They’re highly defensive, and fly when attacked, dropping stones and other stuff (crush) then finishing off with an accurate spike or spear for Critical Damage. Pretty average, but very agile. Maybe a bit of light armour to survive in the wastes.

Birdos

3 HP, 1 Armour, 8 STR, 16 DEX, 10 WIL, Attack (d6 Rocks and up to d12 pieces of Debris)

• A faction of bird people, close-knit communities who roost high in the cliffs of the Wastes and Wilderness, or high towers in the ruins. Love music and dancing.

• Protect their roosts by bombarding invaders with loose debris.

• Critical Damage: Throws a sacred spear to impale their adversary.

Give it a go, and let me know about your creations.

Thanks

Thanks to Will Purves and @gestaltist on the Copy/Paste Discord for their advice when putting this together. Thanks to Yochai Gal for the Cairn Guide for Creating Monsters, and Chris McDowall for all his guides to the process for Mark of the Odd games.