Curio is an on-chain Real-Time Strategy (RTS) game. Players can harvest resources, build bases and defenses, command armies, and capture one another's towers in a rich 2D world, similar to Sid Meier's Civilization and Markus Persson's MiniCraft. Unlike other crypto games that focus on on-chain assets, Curio stores all game logic and state changes on the blockchain, replacing the traditional game server. As a result, game instances are not only fully transparent, but also open to "modding" - any player can interact with and enhance the core game logic via smart contracts.