The series often features the option to play as characters other than Mario, usually Luigi. Earlier games offer an alternating multiplayer mode in which the second player controls Luigi on their turn. Luigi is often only playable by player one in a second, more challenging iteration of the base game, such as in The Lost Levels, Galaxy 2, New Super Luigi U, and the special worlds in 3D Land; these feature lower gravity and reduced friction for Luigi. Later games allow four player simultaneous play.
