Index -> Glossary -> Link
Linking one card to another allows for an ongoing effect that lasts until either card leaves play. The target of a linking card gets an icon in its upper right corner showing what kind of card links to it. (For example, when an ability card links to a unit card, that unit gets a ability link icon.) When two cards are linked, you can mouse over either one of them to see a link icon appear on the other card.
