The Inventor is typically a pro-town role that can hand out "inventions" to other players at night. These inventions are items that other players can use as, typically, one-shot powers. What these items can do vary from game to game and are up to the moderator's discretion, but generally Cop investigations, Doc Protects, and the like. It is also up to the moderator whether the inventor knows beforehand what their items do, how often they can hand them out and how many times they may or may not be able to give to the same player.
Inventors are often paired with a Thief who has the capability to either steal items from the Inventor, or to steal them from the person to whom the Inventor has given the item.
One unique hybrid is the Inventor Thief, who steals inventions from players at night, and then the following night can redistribute that invention like a normal Inventor.