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

parts

15 mechanics, as The Sims does them

core · 3

space & construction

Building placement

Build and Buy modes freeze time while the player lays walls, floors, and objects on a square tile grid; object quality and layout set how efficiently motives can be met.

agents & behavior

Needs decay

Eight motives (Hunger, Comfort, Hygiene, Bladder, Energy, Fun, Social, Room) decay at different rates; low motives drag down mood, and neglect can kill.

agents & behavior

Smart objects

Each of the 150-plus base-game objects advertises motive gains (a refrigerator advertises Hunger, a bed Energy), and Sims query the lot's objects to find interactions.

supporting · 12

agents & behavior

Agent skills

Cooking, Mechanical, Charisma, Body, Logic, and Creativity rise through objects such as bookshelves, mirrors, and chess tables, and gate promotions.

agents & behavior

Autonomy levels

Free will is an option toggle; even with it on, bills, job hunting, exercise, and having children need commands.

progression & goals

Career ladder

Ten career tracks with ten levels each; promotions need skill points and a minimum number of household friends, and change salary and hours.

space & construction

Decoration and beauty

The Room motive reflects lighting, cleanliness, and decorative value around the Sim.

risk & failure

Permadeath

Sims die from neglect or accidents and leave an urn or tombstone; the household continues without them.

agents & behavior

Personality traits

Twenty-five personality points are split across Neat, Outgoing, Active, Playful, and Nice, which change preferred activities and social outcomes.

social relations

Relationship values

Each pair holds a relationship score moved by interactions and eroding without contact; friend counts feed promotions.

social relations

Romance and family

Sims can become partners, marry, and have a baby by explicit command; neglected babies can be taken away by a social worker.

social relations

Social exchanges

Talk, joke, compliment, hug, kiss, tease, slap, and similar interactions succeed or fail on relationship, mood, and personality.

economy & finance

Treasury and budget

Every household starts with 20,000 simoleons regardless of size; wages, bills, and purchases set the balance.

agents & behavior

Utility action selection

Free will scores advertised interactions against current motive levels so the most depleted motive tends to win; players can cancel queued autonomous actions.

watch

1 short with this record on screen
Short 5: The refrigerator knows, opening frameplay · 0:36
rendered · short-05.mp4 · drawn from the dataset

short 5 0:36

The refrigerator knows

transcript

In The Sims, the knowledge of how to eat is stored in the refrigerator.

Every object advertises what it offers. The refrigerator advertises Hunger, the bed Energy. A Sim weighs the offers in reach against what it needs and picks one, and the object brings the script and the animation [1].

Expansions taught Sims new things largely by selling them new objects.

It also meant every behavior was made by hand. The base game shipped with more than 150 objects, and the dataset scores the method 4 out of 5 for authoring cost.

also on the pages for

core loop

build and furnish the lot -> motives decay -> objects advertise motive gains and Sims act or take queued orders -> jobs pay for upgrades -> skills and friendships unlock promotions -> expand house and family

design notes

Will Wright drew on Christopher Alexander's A Pattern Language, treating a house as a set of functional patterns judged by how well they serve the people living in it. Much of the behavioral logic sits in objects: each object advertises which motives it raises and by how much, and Sims with free will enabled choose among those advertisements weighted by their current motives. Sims are deliberately not fully autonomous, since paying bills, finding jobs, exercising, and having children need explicit commands, so the player alternates between architect and caretaker. Build and Buy modes pause time, separating spatial design from the live simulation.

appears in

the paper, 4 sections · 9 chapters · 8 episodes · 1 short
paper

1. Introduction

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

linked from the text

book
ch 3

Chapter 3. Old parts

linked from the text

book
ch 4

Chapter 4. Families

linked from the text

book
ch 6

Chapter 6. Five ceilings

linked from the text

book
ch 7

Chapter 7. What shipped

named in the text

book
ch 8

Chapter 8. Where AI lands

named in the text

book
ch 9

Chapter 9. Vacant lots

named in the text

book
ch 10

Chapter 10. Bets

named in the text

book
ep 2

Where the parts came from

on screen at 1:08 a date is a lower bound, 4:28 the founding games

episode
ep 3

Families across genres

on screen at 4:00 odd couples, 4:35 series and descendants

episode
ep 4
episode
ep 5

The five ceilings

on screen at 0:00 cold open, 0:15 behavior that lives in objects, 5:59 minds made of formulas, 6:27 lifting one ceiling spends another

episode
ep 6

What AI shipped

on screen at 5:26 tools that never reach you

episode
ep 7

Where AI lands

on screen at 4:15 what they'd change

episode
ep 8

Vacant lots

on screen at 1:40 packages

episode
short 5

The refrigerator knows

0:36 · on screen in the short

short

relations

1 stored edges

sources

1
Wikipedia contributors (2026). The Sims (video game). Wikipedia

provenance

runs in log/runs
2026-10-24
created2026-10-24-catalog-gccatalog
2026-10-24
reviewed2026-10-24-review-fixesmaintenance