Battle Towers are special areas set up specifically for Pokémon battles. Trainers register their Pokémon on the first floor and climb up the floors in a number of battles, fighting other trainers one by one. Pokémon that are not found in their Pokédex will not be registered as having been seen. In later games, there are a number of rules that can also be changed within the tower, such as fighting in double battles against the other trainers. Battles conducted here do not award experience or money. Trainers sometimes battle for bragging rights, but they are often rewarded with rare items or points that can be used to buy rare items as well. In Johto (Generation IV only), Hoenn and Sinnoh, the Battle Tower are part of a larger Battle Frontier.