rhYciv

rhYciv is a standalone, high-resolution turn-based empire strategy game. It preserves the map, city, research, production, and tactical-unit rhythm of 1990s 4X games while deliberately focusing the endgame on conquest.

No commercial game installation, CD, DLL, font, rules file, artwork, or save file is required. The repository is designed to be a redistribution-ready base for downstream forks. rhYciv is an independent project and is not affiliated with or endorsed by Take-Two Interactive, 2K, Firaxis, MicroProse, or any other publisher of the Civilization series.

The map screen. Terrain, resources and wildlife are all replacement art; no commercial game files are used.

Gameplay scope

• Explore a procedurally generated world, found cities, improve terrain, trade, research technologies, build wonders, and wage war.
• Diplomacy and multiplayer are not implemented yet.
• New games default to conquest-only victory and permanent elimination.
• Spaceship victory, the throne room, animated advisors/high council, and wonder movies are outside the streamlined product scope.
• The renderer uses a 1920x1080 logical layout, native high-DPI drawing, 128x64 working terrain tiles, 300x300 unit/citizen sources, and map zoom levels from -7 through 16.
• Land and air units have a rear-left silhouette shadow. Naval units have wakes and waterline splashes instead of land shadows.

See the gameplay guide for systems, differences, and controls.

Download

Version 0.2.3 runs on Linux, Windows and macOS. Get it from the latest release:

Platform	Download	Run
Windows x64	rhYciv-0.2.3-win-x64.zip	unzip, run RaylibUI.exe
macOS (Apple silicon)	rhYciv-0.2.3-osx-arm64.zip	unzip, drag rhYciv.app to Applications
macOS (Intel)	rhYciv-0.2.3-osx-x64.zip	as above
Linux x64	rhYciv-0.2.3-linux-x64.tar.gz	extract, run ./RaylibUI
Linux Flatpak	rhYciv-0.2.3-x86_64.flatpak	see below

Nothing else is required. Each download carries its own .NET runtime and the complete art set.

flatpak install --user ./rhYciv-0.2.3-x86_64.flatpak
flatpak run io.github.crhy.rhYciv

The builds are unsigned

Signing certificates cost money this project does not have yet, so macOS and Windows will both try to stop an unsigned download.

On macOS, the app will be reported as damaged or from an unidentified developer. It is neither; that is the quarantine flag. Clear it with:

xattr -dr com.apple.quarantine /Applications/rhYciv.app

On Windows, choose More info then Run anyway at the SmartScreen prompt.

Saves, logs and settings live in rhYciv/ under the platform data directory: ~/.local/share on Linux, %LOCALAPPDATA% on Windows, and ~/Library/Application Support on macOS. Builds before 0.1.0 wrote to AxxCiv/; that directory is migrated on first launch and left in place.

Build and run

The desktop client requires the .NET 9 SDK:

dotnet run --project RaylibUI/RaylibUI.csproj

It launches directly with the bundled ruleset. An external compatible rules directory is optional for mod and scenario testing.

Run the complete validation gate before distributing a build:

./scripts/quality_gate.sh

The gate verifies every attributed asset and the Civilopedia text, asserts that the build version matches the AppStream metainfo, then restores, builds and tests. The same script runs in CI on Linux, Windows and macOS, so what it says locally is what CI will say. Flatpak instructions are in packaging/flatpak/README.md.

Essential controls

• F11: toggle borderless desktop resolution
• Ctrl + mouse wheel: zoom the map
• Ctrl + middle click: reset to 1:1 zoom
• Middle click/drag: center or pan the map
• Hold Ctrl: inspect the tile under the pointer
• Hold Shift: preview unit, road, or trade-route paths
• Shift + right click: move eligible units of the active type
• Ctrl + Alt + arrows: brightness/saturation; Page Up/Down: gamma; Home: reset

Advance artwork. Every shipped asset has a row in ASSET-MANIFEST.tsv recording its author and licence.

Forking and licensing

Code and project-original art are GPL-3.0-only unless an asset’s manifest row says otherwise. Freeciv-derived standalone data remains GPL-2.0-or-later, and Liberation fonts remain OFL-1.1. Every shipped media/data file has a pinned row in ASSET-MANIFEST.tsv.

Start with the documentation index, architecture guide, clean-room status, and contribution rules. Legal and attribution notices are in NOTICE.md.