The D-Link menu allows the player to enable or disable D-Links and switch the Finish Commands equipped to them.

The Dimension Link (ディメンションリンク, Dimenshon Rinku), abbreviated to D-Link, is a feature similar to summoning that appears in Kingdom Hearts Birth by Sleep. It allows the user to summon another character's power from across the worlds.^[1]

Story

Kingdom Hearts Birth by Sleep

Aqua makes three Wayfinders, and she gives two of them to Terra and Ventus the night before she and Terra take the Mark of Mastery exam. After telling the legend behind the Wayfinder, she explains that she added some magic to the ones she made, representing an "unbreakable connection".

As the three of them journey from world to world, the bonds they make with those they meet along the way create D-Links, through the power of their Wayfinders.

When outmatched by Ventus-Vanitas, Aqua clutched her Wayfinder close, asking Terra and Ventus for strength to fight back. Their bond activates Bladecharge, giving Aqua the power she needs to fracture the X-Blade.

Mechanics

The D-Link Gauge.

A Dimension Link can only be activated when the blue D-Link Gauge is full. The gauge is located directly above the HP gauge, and it is filled by picking up blue D-Link prizes, or by using a Balloon Letter. D-Links can be activated by pressing and selecting an enabled link from the list. D-Links cannot be activated if there are temporary allies in the party, and during the battles against Eraqus and Terra-Xehanort in Terra's scenario.

Activating a D-Link immediately restores all HP. While the link is active, the equipped Command Deck is replaced with the deck associated with the link. Additionally, the Command Gauge changes its appearance to reflect the linked character, and a sprite of the character appears above that of the player character. Upon filling the Command Gauge, the player can use a unique Finish command. While the link is active, the D-Link Gauge decreases continuously, and the link is broken when the gauge is empty. Alternatively, the player can deactivate the D-Link early by selecting "Revert" from the D-Link menu, by leaving the area, or by bringing up the main menu.

The D-Link emblem resembles a Wayfinder.

While a D-Link is active, defeated enemies have a chance of dropping a special emblem (シンボルマーク, Shinboru Māku, lit. "Symbol Mark"). The chance of dropping an emblem depends on the D-Link used and the amount of emblems collected, and can range from 5% to 20%; the more emblems the D-Link has, the lower the chances are. Collecting an emblem raises the D-Link's level, which expands its Command Deck and unlocks a unique ability, as represented by the symbols to the left of the linked companion's sprite. Bringing the link up to Level 2 changes the linked companion's sprite, expands the deck again, adds a second ability, and grants access to a more powerful Finish command. Once a D-Link has reached Level 2, any additional emblems collected simply restore the D-Link Gauge.

In the "D-Links" section of the main menu, a list of available D-Links can be seen, along with their deck and abilities. Individual D-Links can be disabled with , and for Level 2 D-Links, the and buttons toggle between the Base and Enhanced version of the D-Link, switching the D-Link's sprite and Finish command.

In the PSP releases of the game, the player can create custom D-Links based on their friends' characters at the Mirage Arena, using the PSP's wireless connection. These D-Links can also be removed or replaced at player discretion. The custom D-Link will operate as a variant of the Terra, Ventus, or Aqua D-Links, depending on which character their friend is using, but its Command Deck and Finish Command will match whatever commands the friend had equipped when the D-Link was created. Regardless of level, these D-Links' sprites are an armored version of the character the friend is playing as. Like the standard Terra, Ventus, and Aqua D-Links, it can be leveled up by collecting emblems, unlocking the appropriate abilities as well as any Advanced or Ultimate commands that were part of the Command Deck. However, the player cannot use any commands that their character wouldn't be able to use in normal gameplay (e.g., Terra cannot use a Faith command within the custom deck).

List of D-Links

Refer to the articles of each character for more details.

D-Link	Description	Abilities		Obtained	Character
		1 emblem	2 emblems
	Rushing attacks.	Overdrive	Auto-Block	Clear the Land of Departure		V	A
	Blast of wind.	Haste	Auto-Counter	Clear the Land of Departure	T		A
	Magic of each element.	Magic Deflector	Auto-Life	Clear the Land of Departure	T	V
	HP Recovery	Auto-Teleport	Double EXP	V: Defeat Vanitas at the Badlands A: Defeat the Unversed at the Front Doors		V	A
	Fire attacks.	Magic Boost	Shell	Clear the Mysterious Tower		V	A
	Charge at enemies.	Protect	Stun Boost	Clear the Mysterious Tower		V	A
	Unique moves for each of the dwarfs.	Gauge Boost	Quickload	Clear Dwarf Woodlands		V	A
	Fairy magic.	Auto-Remedy	Regen	Clear Castle of Dreams	T	V	A
	Fire and sleep attacks.	Focus Saver	Drain	Reach Aurora's Chamber	T
	Fiery spin attack.	Berserk	Attack Deflector	Clear Olympus Coliseum	T	V	A
	Thunder attacks.	Attack Boost	Double CP	Clear Deep Space	T	V	A
	Jumping attacks.	Float	Double Strike	Clear Never Land	T	V	A
	Spin attack that causes status effects.	Munny Plus	Steal	Finish a Command Board game from the menu in which either the "Captain Justice" or "Captain Dark" special events are activated[2]	T	V	A
	—	—	—	Available only during the battle against Vanitas in Ventus's Mind, once he is reduced to 1 HP.		V
	—	Overdrive	Auto-Block	Link with another player's Terra in the Mirage Arena[3]	T	V	A
	—	Haste	Auto-Counter	Link with another player's Ventus in the Mirage Arena[3]	T	V	A
	—	Magic Deflector	Auto-Life	Link with another player's Aqua in the Mirage Arena[3]	T	V	A

Notes and references

• Kingdom Hearts Birth by Sleep commands
• Kingdom Hearts Birth by Sleep
• Abilities