An Extra Link (Japanese: エクストラリンク, Ekusutora Rinku) is a series of five co-linked Link Monsters that spans from one Extra Monster Zone to the other. Monsters involved in the Extra Link are "Extra Linked". This allows a player to control monsters in both Extra Monster Zones simultaneously, and is the only way for a player to use both Extra Monster Zones. Since both are occupied, the opponent cannot use either of the Extra Monster Zones, unless they remove a monster from one of those zones.
A player can create an Extra Link so long as the following conditions are met:
- The player controls a Link Monster in an Extra Monster Zone while the other Extra Monster Zone is unoccupied.
- Three Link Monsters occupy all three central Main Monster Zones on one side of the field. (The player creating the Extra Link can use three opponent's monsters for these.)
- Each of the above Link Monsters must be co-linked with the others orthogonally adjacent to it. (An Extra Link cannot be created if the Link Monsters are only co-linked diagonally.)
In that case, the player who controls the Link Monster in the Extra Monster Zone can Link Summon a second Link Monster to the unoccupied Extra Monster Zone, as long as it would be co-linked to the Link Monster in the Extra Link orthogonally adjacent to it. Performing the Link Summon must not disturb the Extra Link by using the Link Monsters involved as Link Materials.
The final result is a u-shaped chain of five Extra Linked Link Monsters (n-shaped if using Link Monsters in your opponent's Main Monster Zones).