Eonmark

Eonmark is an open-source, Mac-native real-time strategy game written in Rust. Towns project borders. Armies wither on hostile ground. Ages turn with what you learn. A deterministic, fixed-point simulation runs at 20 ticks per second from a command log, and Bevy draws it as calm, matte, flat-shaded low-poly on Apple Silicon (at M0 the renderer draws a ground plane only). Every rule lives in RON data, so you can rebalance a unit or add a faction without touching the engine.

Eonmark is an original game inspired by Rise of Nations (Big Huge Games, 2003). It is not affiliated with or endorsed by Microsoft.

What you do

Planned play, delivered in M3a to M5b. None of this is implemented at M0.

• Found Towns. Each Town projects a border, and you can only build inside your borders.
• Put Yeomen to work. Grain, Lumber and Ore come in at a rate and flatline at a Yield Cap until Trade techs raise it. Lore comes from the Scriptorium and the Scribes you station there, and is exempt from the cap.
• Everything gets pricier the more you own, so growth is a choice, not a default.
• Research twelve techs across four lines at the Scriptorium. The number of techs you know turns the age: Hearth, then Masonry, then Charter.
• Fight on a counter triangle. Once Harrying is researched, unsupplied enemies inside your borders wither unless a Supply Wain is with them.
• Towns cannot be destroyed, only annexed. Capture the enemy Seat to win.

A match is meant to last 20 to 40 minutes. All numbers are starting values and will move during tuning (M6).

Status

Pre-alpha. M0 to M2 are merged: a deterministic fixed-point sim with pathing, movement, replays and a headless CLI, and a macOS window that shows units you can select and move. M3a (economy, Towns, the territory field, construction, gathering and training, all headless) is on PR #26. Nothing is playable as a game yet. The plan, with milestone ids M0 to M9, is in docs/ROADMAP.md. The first playable skirmish is M5b. The first release, v0.1.0, is M8.

Quick start for contributors

You need the Xcode Command Line Tools and rustup. The pinned toolchain (Rust 1.99.0) installs itself from rust-toolchain.toml on your first cargo command.

xcode-select --install
# install rustup from https://rustup.rs if you do not have it
git clone https://github.com/tonianev/eonmark.git
cd eonmark
cargo run -p game --features dev

The game opens on its main menu; New Game starts a skirmish against the Standard bot on plains_1v1 (-- --skip-menu starts it at once, -- --spectate watches the bot play itself). The first build compiles Bevy and takes several minutes (2 min 34 s cold on an M5 Max). Measured numbers for the development Mac and for CI are in docs/BUILD_TIMES.md. Later builds are much faster because dev turns on dynamic linking. Never ship a build with dev.

To run the CI gates locally, install just (brew install just) and run just ci; see CONTRIBUTING.md.

Headless path

Most of Eonmark is a plain Rust library with no engine dependency. You can work on it on any OS, without a GPU, and the tests finish in seconds:

cargo test -p sim
cargo run -p sim-cli -- selftest
cargo run -p sim-cli -- data-check data

selftest runs the same scripted ticks twice on two threads and prints two identical hashes. data-check loads and validates everything under data/. See CONTRIBUTING.md for the data-first workflow.

Platforms

Eonmark is supported and released on Apple Silicon macOS. The game crate must keep compiling on Linux, and CI enforces this (the game-linux job), so contributors on Linux can work on it. Running the game there is unsupported. Windows is not checked. The sim, rules, ai and sim-cli crates run everywhere.

Installing a release

From v0.1.0 (M8). There are no releases yet.

Releases are published on the GitHub Releases page as Eonmark-<version>-macos-arm64.zip with a SHA256SUMS file. The app is ad-hoc signed and not notarized, so macOS blocks the first launch.

1. Download the zip with Safari. curl and gh skip the quarantine flag, so the steps below will not match.
2. Unzip and move Eonmark.app to Applications.
3. Double-click it. macOS says the app cannot be opened. Click Done.
4. Open System Settings > Privacy & Security, scroll down, and click Open Anyway next to the Eonmark message. The button is shown for about an hour after the blocked attempt.
5. Confirm with your password or Touch ID. The app opens. Later launches are not blocked.

Terminal alternative to steps 3 to 5:

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

Verify the download, in the folder that holds the zip and SHA256SUMS:

shasum -a 256 -c SHA256SUMS

Project layout

Path	What it is
crates/sim	Deterministic fixed-point simulation. Pure Rust, no engine dependency.
crates/rules	RON schema, loader and validator for data/. Computes rules_hash.
crates/ai	Scripted skirmish opponent behind the AiController trait.
crates/game	The Bevy presentation layer and the eonmark binary. The only engine crate.
crates/sim-cli	Headless tooling: selftest, data-check and hash-dump now; verify, bench (M1) and play-bots (M5b) later.
data/	Every rule and number, in RON. Integers only: time in deciseconds, distance in tiles.
assets/	Fonts, UI, models, audio. Each file has a row in assets/ATTRIBUTION.md.
docs/	Architecture, determinism, data format, build times, roadmap, design notes, ADRs.
scripts/	Bundle, asset check and naming check scripts used by CI and just.

Design principles

1. The simulation is deterministic. Same seed and commands give the same hash on every machine. Fixed-point math, no floats, one seeded RNG. See docs/DETERMINISM.md.
2. Everything is in data. A gameplay constant in Rust is a bug. See docs/DATA_FORMAT.md.
3. Calm, matte look. Flat-shaded low-poly, no glow, no bloom, readable at a glance.
4. Replays are always on. Every session writes a replay (from M2), and sim-cli verify re-simulates it (M1).
5. CI is the gate. just ci runs locally what CI runs. The PR checklist is a guide; CI decides.

Contributing

Read CONTRIBUTING.md for setup, the data-first path and the PR rules, GOVERNANCE.md for who decides what, and AI_CONTRIBUTIONS.md for how AI tools are used here. Issues labeled good first issue can be finished with cargo test -p sim or sim-cli on any OS. Questions go to GitHub Discussions. The CODE_OF_CONDUCT.md applies in every project space.

License

Code and data (crates/, data/, docs/, scripts/) are dual-licensed under MIT OR Apache-2.0, at your option. See LICENSE-MIT and LICENSE-APACHE.

Original assets under assets/ are dedicated to the public domain under CC0-1.0. See assets/LICENSE-ASSETS.md.

Third-party assets under assets/ keep their own licenses (CC0-1.0, CC-BY-4.0 or OFL-1.1) and are listed in assets/ATTRIBUTION.md.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.