Portal (Gameplay element)

Portal is a gameplay element introduced in Kingdom Hearts 3D: Dream Drop Distance. They are a special type of communication system that allow characters from various Dream Worlds communicate, sometimes, even transport from one version of that world to another.

Story
In Riku's side of Traverse Town, Joshua explains that he arrived there through a portal, which he can also use to pass between the different versions of Traverse Town. When Riku asks to be transported to Sora, Joshua explains that he can't do that, because the portal "can only be used by the one who holds Rhyme's dreams."

After defeating Xehanort's Heartless in The World That Never Was, Riku enters Sora's side through a portal. This portal can also be used to return to the World Map of Riku's side.

Link Portals
Link Portals are a type of portal that can be found in all Sleeping Worlds. They give special challenges for the protagonists, Rare Nightmares to battle, other Spirit's party or even allow them to battle stronger versions of the bosses, rewarding the player with Droplets, Dream Pieces, and other prizes if they are completed. Each portal belongs to a "player", usually named from a Final Fantasy character, like Auron, for example.

Mechanics
After the first few drops, Link Portals begin appearing troughout the worlds. They are displayed as pink dots in the lower Touch Screen, but they can't be seen in the top screen. When the player moves near the point where the portal is located, a small sign with the name of the owner, the difficulty rank, represented by five stars, and a symbol of the type of challenge or the Spirit Party of the portal will appear in the Touch Screen. If the player touches that sign, more details about the Link Portal will appear in the top screen. After reading the details, the player can decide to open or not the Link Portal.

There are four different types of Link Portals:
 * Battle Portals: These portals give the player a series of Nightmares to battle, according to another "player" Spirits. It also gives a "Bonus Objective" to be accomplished during the battle like deefeating all Nightmares in a set time limit or doing a number of Flowmotion attacks. After opening the battle Portal, the word "start" will appear. After cleraing the portal, either accomplishing the bonus objective or not, the word "finish" will appear, followed by the results of the portal, telling the player what was obtained. The player receive extra Drop Points and one of several prizes, like a Dream Piece. If the Bonus Objective was achieved, one of various possible bonus prizes will also be received.


 * Friendship Portals: These portals allow the player to temporarily borrow another player's Spirits. If this portal is activated, the player Spirits will be temporarily exchanged for the Friendship Portal Spirits, which come with the Link Gauge full and the HP gauge replaced by a time gauge divided in four segments that deplet over time. When that gauge runs out, the Spirits are exchange with the player Spirits again.


 * Special Portals: These portals pits the player against Rare Nightmares and give even better prizes, like Dream Eater recipes. There are six Special Portals for each character in each world, with the exception of The World That Never Was, that has only three. Only one will be open in any given world per drop. After beaten, they can not be entered again unless the player completes all of them. After all are beaten with one character, that character will receive the End of Pain Keychain.


 * Secret Portals: These portals are unlocked after beating the game. In them, the player can battle stronger versions of the bosses of the world they are in. After all are beaten with one character, that character will receive the Unbound Keychain.