Arena Mode

Joint Struggle is the new multiplayer mode featured in Kingdom Hearts Birth by Sleep. You will be able to wirelessly connect with fellow players to be able to play in multiplayer. In this mode, up to six players can take on the role of Terra, Ventus, or Aqua, the Keyblade warriors wearing their armor from the secret ending of Kingdom Hearts II Final Mix, rather than their usual gameplay attire.

The names of who is playing with you appear above their respective character, and while fighting their HP is displayed like someone who is in your party.

Gameplay
In a new world called the Mirage Arena, three players can access and engage in battles for cooperative play. The Mirage Arena is a world exclusive to Joint Struggle.

Through this multiplayer mode, items and other bonuses can be transferred between single and multiplayer modes. Unique elements of battle include rescuing friends trapped by the Unversed, and continuously pressing the button to heal fallen players. Players may customize their displayed name and the color of their armor. At the end of a completed playing session, winning medals are distributed on a results screen.

The faceshot of Terra, Ven, and Aqua seen in the HP bar is of their helmets. A rating system also appears, showing a level of who stands in what place by displaying differently colored symbols.

The Joint Struggle is also the only place where the Friendship Commands will work properly. Most of them can only be purchased within the Mirage Arena to begin with (excluding Confetti and Fireworks).

Matches

 * Day of Reckoning - Rank 1
 * Sinister Sentinel
 * Risky Riches
 * Wheels of Misfortune
 * Combined Threat
 * A Time to Chill
 * Harsh Punishment
 * Treasure Tussle
 * Copycat Crisis
 * Weaver Fever
 * Dead Ringer
 * Keepers of the Arena
 * Villains' Vendetta