A Multi-User Dungeon, or MUD, is a type of online game that combines elements of role-playing, adventure, and social interaction. Players navigate through a virtual world, often represented by text, where they can explore, solve puzzles, and engage in combat with other players or computer-controlled characters. MUDs typically allow players to create their own characters and develop skills over time. Originally developed in the late 1970s, MUDs laid the groundwork for many modern online games and virtual communities. They often feature a rich narrative and allow for player collaboration, making them a unique blend of gaming and storytelling. MUDs have inspired various genres, including MMORPGs and text-based games.