Luigi is Mario's younger but taller twin brother, the secondary protagonist of the Super Mario franchise, and the main protagonist of the Luigi's Mansion series. Throughout his life, he has lived in Mario's shadow, developing both cowardly and heroic tendencies. Despite this, Luigi has helped and fought alongside his brother on many occasions. Mario Bros. for the Game & Watch marks his first appearance, in which he is an exact copy of Mario. He went on to gain a different color and be used to facilitate a second-player option. However, as Luigi established himself throughout the Super Mario franchise, he gained his own identity as a character.