A Gate Trainer is a small card available in Bakugan: Armored Alliance products. It is a rectangular card with metal inside, similar to Gate Cards from Bakugan Battle Brawlers. It can be found in all six Factions, as well as Diamond. Gate Trainers are not used in the game and are instead intended to be used for trick shots and practice. The primary reason for their inclusion is to prevent the actual cards from being bent or damaged in the packaging.
The Gate Trainers were replaced by Gate Cards.