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Introduction

reTS is an in-development clean-room project to build a faithful, standalone, moddable reimplementation of the Westwood isometric RTS engine behind the Command & Conquer titles Tiberian Sun, Red Alert 2, and Yuri's Revenge.

Last verified against the project charter and release state: 2026-07-21.

Current availability

The documentation site is public. The engine source, binaries, playable client, and native modding tools are not publicly released yet.

What exists today

  • A headless, deterministic simulation core: engine systems are reverse-engineered from the retail binaries, ported, and pinned by binary-derived oracle tests before anything is considered done.
  • The verified slice of that work is published as it completes in the Original Engine Reference, which now spans combat, data/rules interpretation, presentation and UI, and multiplayer synchronization systems.
  • The Devblog narrates the reverse-engineering and build work as it happens, system by system.
  • None of this adds up to a playable game yet — there is no public client, engine source release, binaries, or modding tools. See For players for exact availability.

What makes reTS different

  • Accuracy is the bar. Implemented systems are matched to recovered behavior and pinned by oracle tests so they cannot silently drift.
  • Standalone and clean-room is the destination. The future release will run without original executable code and will ship no game assets; the standalone client is not complete today.
  • Multi-version by proof. Confirmed differences are modelled rather than averaged away. Unverified versions remain explicitly pending.
  • Modern layers come after fidelity. Tooling, configurable limits, modern presentation, and native scripting are additive roadmap layers. They are not presented as shipped features before their underlying engine systems land.

Who this site is for

TrackYou are…Start here
PlayersSomeone who wants to run and play reTSFor players
ModdersA map/mission/game-mode/content authorFor modders
ContributorsA developer who wants to build on reTSFor contributors
Engine researchersSomeone looking for verified original-engine behaviorOriginal Engine Reference
Project followersSomeone following milestones and design decisionsDevblog

Each stream publishes only what its audience can use now. Player, modder, and contributor guides expand when the corresponding capability ships; the Engine Reference accepts only completed, verified systems; the Devblog records the journey as it happens.