A Locator Card, known as a Puzzle Card in the manga and Japanese anime, was a clear card with a prismatic coating containing a small portion of a map of Domino City. There was one given to each participant of the Battle City tournament.
Duelists wagered their Locator Cards in Duels. The eight Duelists to collect six Locator Cards became finalists. If a player ran out of Locator Cards, they were disqualified. In the manga it was explained that there were exactly forty-eight Puzzle Cards issued, each containing one of the forty-eight components of the map in a 6x8 grid.
By stacking the forty-eight cards a map of the city would be formed. In the manga, stacking six cards would at least create a partial map and a light would shine on one spot indicating the location of the finals. In the anime, by inserting six cards in a Duel Disk a holographic projection of the location of the finals would be produced.