RimWorld Ideology is an expansion for the colony sim RimWorld that adds custom belief systems, letting players define the rituals, morals, and social structures their colonists live by. It deepens the game's narrative simulation by giving ideology a direct effect on colonist behavior and relationships.

Players can found and evolve their own faith or philosophy, from peaceful traditions to more extreme ones, with rituals that boost morale or unlock unique benefits. It builds on the base game's colony management and storytelling systems rather than replacing them.