Multi-User Dungeon: MUD1 or simply MUD is an online game where multiple players can simultaneously explore a dungeon using a text-based interface. When logging in to the game the player starts with creating a character, which consists of a name and sex. The aim of the game is to become a wizard or witch. To become a wizard a player must accumulate 102,400 points from the accumulation of treasure (and then dumping it in the swamp) and killing other creatures or players. Once the player becomes a wizard he or she becomes a game operator with additional powers including immortality.
The world is described through text snippets and the player is encouraged to maintain a map using pen and paper. To move around the game uses a text parser similar to early text adventures. Additionally the player can look around and interact with various objects and characters. Since the game allows many people to be connected at once textual chatting is a large part of the experience.
Characters have a stamina, strength and dexterity statistic which used for fighting. Dexterity is the chance of striking the enemy, strength determines the amount of damage done and stamina the amount of damage that can be had before dying. Fleeing from a fight loses the player points, and the victor wins points. When dying in a fight the player has to start over completely. Stamina regenerates when using the sleep command or when not playing the game. The statistics are increased by increasing the player level which is based on the current score of the player.
There are two different deaths in the game. Dying in a fight (stamina drops to 0) results in a permanent death. Other events such as traps or jumping of a cliff results in a temporary death. The player is booted from the game and all items are dropped. They must be recovered manually.