Versus Mode

Versus Mode (VSアリーナモード) is a feature exclusive to the PSP versions of Kingdom Hearts Birth by Sleep. It allows up to 6 players to fight one another in various arenas. As with other events occurring in the Mirage Arena, players appear as Terra, Ventus, or Aqua, wearing their Keyblade Armor, rather than their usual gameplay attire.

Mechanics
When setting up a Versus Mode event, players can choose between a Free-for-All or Team Match, choose between using Preset Decks (専用デッキ), or players' own decks, and set the time limit and number of players. When playing with players' own decks, a maximum of 3 players can participate. When playing with preset decks, up to 6 players can participate.

After getting to the center of the Hub, players can choose an arena to battle in, choose a team in case of a Team Match, and in the case of using preset decks, one of five different deck types.

During a battle, players have a score that goes up each time damage is dealt. Using a specific command after knocking back an opponent gives a score bonus, +10 for Victory Pose, +20 for Confetti, and +30 for Fireworks. Attacking an opponent after using Taunt gives +5 bonus points, +40 when using a Reprisal command. Dimension Links are unavailable. When a player's HP reaches 0, they are revived on a random place on the map. Players can destroy pots on the map, which drop HP prizes, and reappear after 2 minutes. At the end of a match, medals are awarded based on the players' scores and number of participants.

When using preset decks, players get predetermined stats based on the character used, the time limit, and the amount of players. Each character has a preset set of action commands, and the default Finish command. Shotlocks are unavailable. When starting a match, each player has 3 battle commands, from the commands available for their deck type. When getting knocked back, one of the commands is dropped and bounces around on the field. Any player that touches a bouncing command adds it to their deck, replacing the oldest command if their deck already has 8 commands. Using Deck Scramble makes a player lose all their commands. When a player's HP reaches 0, they drop commands until they have 3 commands in their deck, or they drop 1 command when they have fewer than 3 commands in their deck. Pots now have a 50% chance of releasing a random battle command, and a 10% each for dropping one of 4 exclusive commands or Vanish. Players that have a or Black command in their deck at the end of the match, get 10% added or substracted from their score, respectively, for every copy.

Arenas
Players can battle in six different arenas.
 * Olympus Coliseum: The Coliseum
 * Mirage Arena: The Mirage Arena's basic arena.
 * The Badlands: An unique map with rock platforms and a twister that makes you fly up
 * Disney Town: The same arena used in Treasure Tussle
 * Deep Space: A map based on the Ship Hub. Low gravity allows users to jump higher and fall slower. After 30 seconds, and every 70 seconds after that, a flash inflicts either Stun,, Blind, Confusion, or . The flash can be avoided by standing on one of the floating platforms.
 * Castle of Dreams: A map based on the Mousehole. Yarn balls can be used to knock opponents away.