4XCIV, built by Million on Mars, is developing a real-physics solar-system civilization simulation led by agentic AI officers. Its world is grounded in real astronomical and mission data: 37 tracked planets, moons, and asteroids are presented with real orbits, imagery, lighting, and surface detail drawn from eight datasets, including HiRISE, Voyager, Cassini, and New Horizons. Where measurements are unavailable, the project makes known gaps visible.

Visitors can explore the solar system for free in a browser without logging in. The 4XCiv Play game, currently in crew testing, builds a strategy experience on this foundation. Players can survey terrain, establish colonies, craft from a 173-item catalog, plan real interplanetary transfers, and fight within the solar system. The site also offers the Canon, a searchable collection of the project’s thesis, design pillars, and worldbuilding, plus a Devlog documenting development. AI-agent interfaces for research queries and simulation actions are planned, but are not yet available.