Legendary is a special ability in Magic the Gathering Tactics.
Only one legendary figure of the same name can exist on the board. If a second legendary figure of the same name is summoned, both are destroyed.
Legendary figures are considered to be unique, therefore only one can exist at a time.
The traditional Magic card game has went through multiple stages of defining legendary.
In Magic Tactics, there is almost infinite room to describe any rules associated with abilities.
The practical play of legendary are the same in both games.