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

parts

6 mechanics, as Terra Nil does them

core · 2

space & construction

Building placement

Buildings have placement rules: wind turbines go only on stone tiles and power toxin scrubbers, which clean soil so irrigators can green it.

economy & finance

Treasury and budget

Each restored tile earns points, and points are the only currency for buildings and upgrades, so a map can stall if spending outruns restoration.

supporting · 4

environment & ecology

Habitat suitability

Restored biomes attract deer, birds, fish, and bears.

environment & ecology

Hydrology

Pumps refill dried riverbeds and tools carve new rivers.

progression & goals

Scenario objectives

Each map sets restoration targets before the player can recycle buildings and leave.

space & construction

Terraforming

Tools create new rivers and some stone tiles.

core loop

place wind turbines on rock -> power toxin scrubbers that clean soil -> irrigate and pump water into riverbeds -> upgrade to grow wetlands, meadows, and forest -> attract animals and restore weather -> recycle every building and leave

design notes

It inverts the city-builder loop: growth is measured in restored tiles rather than population, and points earned per restored tile are the only currency for further buildings, so efficient placement compounds. The final step requires recycling all infrastructure to build an airship and leave, so a layout must be removable as well as productive. Subgenre is set to city-builder because its lineage is placement and budget puzzles rather than population or evolution modeling. It began as a Ludum Dare 45 entry in October 2019.

appears in

the paper, 2 sections · 2 chapters
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 4

Chapter 4. Families

linked from the text

book
ch 9

Chapter 9. Vacant lots

linked from the text

book

sources

1
Wikipedia contributors (2026). Terra Nil. Wikipedia

provenance

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