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

parts

24 mechanics, as Oxygen Not Included does them

core · 6

resources & production

Byproducts and waste

Machines and duplicants emit polluted water, polluted oxygen, carbon dioxide, and heat; a natural gas generator consumes 90 g/s of gas for 800 W and outputs 67.5 g/s polluted water and 22.5 g/s CO2.

physics & materials

Fluid and gas simulation

Every tile holds one gas, liquid, or solid with a mass; gases diffuse and equalize when a chamber is opened, and liquids drain under gravity, so breathable oxygen must be produced and carbon dioxide managed.

logistics & networks

Fluid pipe networks

Gas and liquid pipes carry packets between buildings; a liquid pipe segment holds 10 kg and moves packets once per second, capping a line at 10 kg/s, and pipe contents exchange heat with their tiles.

physics & materials

Heat transfer

Cells exchange heat each 0.2 s tick with q = dT x dt x k x 1000, with multipliers for solid-gas and liquid-liquid contact; insulated tiles divide conductivity, and temperature thresholds melt, freeze, boil, or damage things.

agents & behavior

Mood and breakdowns

Morale is the sum of timed buffs (Mess Hall +3, Private Bedroom +3, food up to +16, decor up to +12) compared to an expectation that rises with skills learned; each point under adds 2.5% stress per cycle up to 25%, full stress triggers a stress response, and 8 or more points over can trigger overjoyed responses.

agents & behavior

Work priorities

Every errand carries a priority, and each duplicant has per-errand-type priorities on the Priorities screen; duplicants pick the highest available errand and favor tasks they are good at.

supporting · 18

agents & behavior

Agent skills

Skill points are spent on skills, which raise morale expectations.

biology & health

Animal husbandry

Critters are ranched for food and for their conversion of inputs into useful outputs.

space & construction

Building placement

environment & ecology

Contagion

Germs live on tiles, items, gases, and liquids; exposure past per-germ thresholds gives a contraction chance of 0.5 - 0.5 x tanh(resistance / 4).

resources & production

Crop cultivation

Plants need specific temperatures, atmospheres, and irrigation.

information & legibility

Data overlays

Oxygen, temperature, power, plumbing, and germ overlays show hidden cell state.

space & construction

Decoration and beauty

Decor around a duplicant is compared to its recent average and feeds morale.

control & automation

Designation orders

Dig, build, mop, and deconstruct orders placed on tiles.

multiplayer & persistence

Modding API

Steam Workshop mods are C# assemblies patched in with Harmony.

agents & behavior

Personality traits

Traits such as Germ Resistant or Allergies change resistances and stress reactions.

resources & production

Power grid

Coal, hydrogen, natural gas, and manual generators on wires and batteries; overloaded circuits take damage.

world generation

Procedural terrain

Asteroids are procedurally generated.

space & construction

Room recognition

Enclosed rooms that meet requirements become Mess Halls, Bedrooms, and similar rooms that grant morale buffs.

control & automation

Signal circuits

Automation wires, sensors, and logic gates control doors, pumps, and generators; extended by the Automation Innovation update.

resources & production

Spoilage

Food rots unless refrigerated or kept in a sterile atmosphere.

resources & production

Storage and buffers

progression & goals

Tech tree

Research unlocks buildings.

core loop

dig into the asteroid -> lay out rooms, pipes, and wires -> duplicants perform prioritized errands -> oxygen, heat, germs, and waste redistribute tile by tile -> stress and shortfalls surface -> rebuild toward closed, sustainable loops

design notes

Each cell holds one element with a mass and a temperature, and heat moves between cells every 0.2 s tick by conduction, so insulation, phase changes, and overheating machines follow from one rule rather than from per-building scripts. Most machines emit byproducts (a natural gas generator makes 800 W plus polluted water and carbon dioxide), so the long game is closing loops so waste becomes input. Mood uses a morale-versus-expectation gap: learning skills raises a duplicant's expectation, so better-trained colonists need better food, rooms, and decor. Wikipedia names Dwarf Fortress, Prison Architect, and The Sims as design influences.

appears in

the paper, 3 sections · 6 chapters · 4 episodes
paper

3. The catalog

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 2

Chapter 2. Six layers

linked from 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 10

Chapter 10. Bets

named in the text

book
ep 3

Families across genres

on screen at 4:11 odd couples

episode
ep 4

Why deep systems are hard to read

on screen at 3:53 expensive and hidden, 6:17 choosing a point

episode
ep 9

Bets worth making

on screen at 1:27 what a bet contains

episode

relations

3 stored edges
influenced by
influenced by
influenced by

sources

7
Wikipedia contributors (2026). Oxygen Not Included. Wikipedia
Klei Entertainment (2026). Oxygen Not Included on Steam. Steam
Oxygen Not Included Wiki contributors (2026). Morale. Oxygen Not Included Wiki (wiki.gg)
Oxygen Not Included Wiki contributors (2026). Germs. Oxygen Not Included Wiki (wiki.gg)
Oxygen Not Included Wiki contributors (2026). Thermal Conductivity. Oxygen Not Included Wiki (wiki.gg)
Oxygen Not Included Wiki contributors (2026). Liquid Pipe. Oxygen Not Included Wiki (wiki.gg)
Oxygen Not Included Wiki contributors (2026). Natural Gas Generator. Oxygen Not Included Wiki (wiki.gg)

provenance

runs in log/runs
2026-10-24
created2026-10-24-catalog-gbcatalog
2026-10-24
reviewed2026-10-24-review-fixesmaintenance
2026-10-25
reviewed2026-10-25-contributor-readinessmaintenance