— where fruitbats sparkle
Guilds on Discworld MUD are more like professions or occupations than clubs. The Guild is what shapes your character. Unique commands are taught at your guild and choosing a guild allows you to advance more cheaply at the lower levels.
Although most people join guilds, it is not required that you join one. Before you join a guild (or if you don't join one), you are known as an Adventurer. As such, you can only advance your skills by teaching yourself or having other players teach you.
It should be noted that Assassins' Guild members, upon reaching level 75, are required to pass a practical examination known as The Run in order to keep advancing in the guild. Once this happens, your character automatically becomes a PK (player-killer) character. The Wizards' Guild has an order (The Last Order) which contains all PK members as well.
Most guilds have multiple specialisations which further shape your character development. When you get to a certain level within the guild, your specialisation choices will be presented to you. Some specialisations come with different primary skills (meaning those skills are cheaper to advance) or with specialized commands. Choose a guild below to see the specialisations (if available) in each.