one dataset · paper, tables, graph, wiki
simgrammar the grammar of simulation

parts

25 mechanics, as RimWorld does them

core · 7

risk & failure

Adaptive threat scaling

Raid strength scales with colony wealth, number of colonists, and difficulty, so growth raises danger.

biology & health

Injury body model

Bodies are hierarchies of parts with hit points, bleeding, infection, scars, and prosthetics that change capacities like moving and manipulation.

agents & behavior

Memories and thoughts

Every mood effect is an itemized thought with a source and expiry, visible in the needs tab.

agents & behavior

Mood and breakdowns

Mood below trait-adjusted break thresholds triggers minor, major, or extreme mental breaks; high mood can grant inspirations.

agents & behavior

Needs decay

Colonists track food, rest, recreation, comfort, beauty, and other needs whose levels feed mood.

narrative & generation

Storyteller director

Selectable storytellers (Cassandra, Phoebe, Randy) choose incidents using a threat budget derived from colony wealth and time since the last major event.

agents & behavior

Work priorities

A work tab matrix sets 1-4 priorities per colonist per job type; colonists self-assign.

supporting · 18

information & legibility

Agent inspection

agents & behavior

Agent skills

agents & behavior

Autonomy levels

Drafting switches a colonist from self-assigned work to direct player control for combat or emergencies.

resources & production

Crop cultivation

space & construction

Decoration and beauty

control & automation

Designation orders

environment & ecology

Fire spread

multiplayer & persistence

Modding API

XML definitions and C# assemblies, usually patched in with Harmony, distributed through Steam Workshop.

risk & failure

Permadeath

agents & behavior

Personality traits

world generation

Procedural characters

conflict & defense

Raid defense

social relations

Relationship values

space & construction

Room recognition

resources & production

Spoilage

resources & production

Storage and buffers

agents & behavior

Utility action selection

watch

2 shorts with this record on screen
Short 1: The five most common parts, opening frameplay · 0:38
rendered · short-01.mp4 · drawn from the dataset

short 1 0:38

The five most common parts

transcript

The five parts that turn up most often in simulation games don't simulate anything.

We broke 179 of them into their parts. First is the pause button, in 46 percent of them. Then placing buildings where you like, support for mods, a tech tree, and scenario goals.

Production chains come sixth, and they're the first part on the list that models something in the world: ore into plates, plates into gears.

The parts a game is known for are rare. RimWorld's storyteller, its mood breaks and its body-part injuries each show up in fewer than ten catalog games.

also on the pages for

Short 4: Decorating makes the raids bigger, opening frameplay · 0:36
rendered · short-04.mp4 · drawn from the dataset

short 4 0:36

Decorating makes the raids bigger

transcript

In RimWorld, decorating your colony makes the raids bigger.

Before every raid the game adds up your colony's wealth and your colonists and turns the total into a budget for the attackers. Wealth starts adding to that budget above 14,000 and keeps adding up to a million [1].

So experienced players keep their colonies plain. They skip the statues and the fine furniture so the raids stay small.

None of it is on screen. The formula lives on the community wiki, and the dataset scores the mechanic 2 out of 5 for legibility, the level where players understand it only through wikis.

also on the pages for

core loop

designate work -> colonists self-assign by priority -> needs and moods shift -> storyteller injects events -> colony adapts or collapses

design notes

Tynan Sylvester describes RimWorld as a story generator. Its systems are chosen for how legible and story-relevant their outputs are rather than for realism: thoughts are itemized with sources and durations, injuries are named body parts, and raids scale with colony wealth to keep tension.

appears in

the paper, 4 sections · 10 chapters · 7 episodes · 2 shorts
paper

3. The catalog

linked in this section of the paper

paper
paper

4. A grammar of simulation games

linked in this section of the paper

paper
paper

5. The structure of the design space

linked in this section of the paper

paper
paper

Appendix A. Game catalog

linked in this section of the paper

paper
catalog

The catalog

listed with its year, developer, subgenre, and number of mechanics

book
ch 1

Chapter 1. Same parts

linked from the text

book
ch 2

Chapter 2. Six layers

named in the text

book
ch 3

Chapter 3. Old parts

named in the text

book
ch 4

Chapter 4. Families

linked from the text

book
ch 5
book
ch 6

Chapter 6. Five ceilings

linked from the text

book
ch 8

Chapter 8. Where AI lands

named in the text

book
ch 9

Chapter 9. Vacant lots

linked from the text

book
ch 10

Chapter 10. Bets

linked from the text

book
ch 13
book
ep 1

Every simulation game is made of the same parts

on screen at 0:00 cold open, 0:32 rimworld, in parts, 3:01 where identity lives

episode
ep 2

Where the parts came from

on screen at 6:26 parts that waited

episode
ep 3

Families across genres

on screen at 4:07 odd couples, 7:31 close

episode
ep 4

Why deep systems are hard to read

on screen at 3:21 harder to balance, 5:51 choosing a point

episode
ep 5

The five ceilings

on screen at 2:39 ticks per second, 3:47 what a player can follow, 4:59 minds made of formulas

episode
ep 7

Where AI lands

on screen at 2:20 explanation by hand, 4:14 the most exposed mechanics

episode
ep 9

Bets worth making

on screen at 3:48 a colonist with a memory

episode
short 1

The five most common parts

0:38 · on screen in the short

short
short 4

Decorating makes the raids bigger

0:36 · on screen in the short

short

relations

1 stored edges
influenced by

sources

1
Wikipedia contributors (2026). RimWorld. Wikipedia

provenance

runs in log/runs
2026-10-23
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2026-10-24
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2026-10-25
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2026-10-25
reviewed2026-10-25-store-ids-pilotcatalog