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

core loop

set geological, atmospheric, and biological rates -> climate and biomes evolve -> taxa spread, mutate, and diversify -> one sapient species advances through seven ages -> pollution, war, and disasters feed back on climate -> spend energy on interventions

design notes

Will Wright and Fred Haslam built SimEarth with James Lovelock as adviser, and its models encode Gaian feedback: volcanic dust cools the planet, warming melts ice caps and raises seas, and life alters atmospheric gas fractions shown to three decimal places. The player mostly acts through control panels that set rates such as continental drift, reproduction, and mutation, plus energy-priced interventions (50 units per terrain square, 500 per terraforming device), so play is closer to tuning coupled systems than to directing agents. Scenarios include Daisyworld, Lovelock's minimal model of temperature regulation by daisy color, and terraforming Mars and Venus.

relations

10 stored edges
uses

God powers

Placing terrain, life, monoliths, oxygen generators, and terraforming devices costs energy (50 per terrain square, 500 per device) from a budget that grows with planetary development.

core
uses

Natural selection

Taxa from prokaryotes to mammals spread and diversify by environment, with player-set reproduction and mutation rates; mass extinctions are often followed by renewed radiation, and any multicellular taxon can become sapient.

core
uses

Planetary climate

Atmospheric composition, temperature, ocean level, and biomes evolve together under Gaian feedback; volcanic dust cools, warming melts ice caps, extreme heat boils oceans, and Daisyworld reduces it to daisies regulating temperature.

core
uses
supporting
uses
supporting
uses
supporting
uses

Random disasters

Hurricanes, wildfires, earthquakes, tsunamis, and meteors occur, with disease and pollution scaling with population.

supporting
uses
supporting
uses

Terraforming

Mars, Venus, Ice Planet, and Dune scenarios ask the player to make hostile planets habitable.

supporting

backlinks

computed from other records

sources

1
Wikipedia contributors (2026). SimEarth. Wikipedia

provenance

runs in log/runs
2026-10-24
created2026-10-24-catalog-gdcatalog