Half-Earth Socialism: The Game

This repo includes:

• hes-engine defines the model that drives the game.
• hes-game is the game itself, which is mostly a visual layer over the engine.
• hes-editor is an editor to change parts of the game/engine, e.g. what projects are available, their parameters, etc, and is used to build custom .world files that can be loaded into new games.

Note that there are effectively two versions of the game: web and native. We don't include the editor for the web version but that should be the only major difference between the two. However worlds created in the editor can be used in the web version.

We also include a version of the Hector simple climate model that we've adapted to run in the browser. The process of building Hector for WASM is complicated so pre-compiled versions are included here.

For native (i.e. non-web) builds we instead use a Rust wrapper for Hector.

Editor

This video walks through an example of how to use the editor.

Translations

The game is already translated into 8 languages thanks to volunteers! If you'd like to translate the game into your language there are examples in game/translations to work from. Open an issue and include the CSV and we will try to get it into the game quickly.

Note there are some aspects of our internationalization system that need improvement (how we handle pluralization, for example).

Setup & Dependencies

git submodule init
git submodule update
cd game/assets/js && npm install -d

Building was last tested with Rust stable 1.89.0 (29483883e 2025-08-04).

Debugging

Debug options can be specified through the env vars DEBUG and DEBUG_VIEW, e.g. with:

DEBUG=SKIP_TUTORIAL,ALL_PROJECTS,SKIP_EVENTS DEBUG_VIEW=Plan cargo run

See game/src/debug.rs.

Running

You can use just to run most tasks:

Available recipes:
    run         # Run the game.
    surfaces    # Generate biome surface textures and regional climates.
    sharing     # Generate sharing images.

Releases

You can play it at:

• half.earth
• Steam (Windows/macOS/Linux) (Account needed)
  • Note: The build process for the Steam version is more complicated so it's less likely to be up-to-date.
• Itch.io (Windows/macOS/Linux)
• Download the latest version in Releases

Community

We have a Discord for the game and book here.