RimWorld is a sci-fi colony simulation game developed and published by Ludeon Studios. Released on Steam on October 17, 2018, the game drops players onto a distant world with a handful of survivors and tasks them with building a functioning colony from scratch. An AI storyteller generates events to shape each run into its own distinct story, from pirate raids and disease outbreaks to unexpected visitors and wildlife attacks. With deep systems covering colonist relationships, crafting, combat, medicine, and trading, and an active modding community on Steam Workshop, no two playthroughs play out the same way.