Each Gwent deck is built with one Leader card. Leader cards determine the deck's faction. Each Leader comes equipped with a powerful ability for turning the tide of battle.
Leader cards may only be used once per match; using a Leader card is the same as using a regular card, and the player's turn will end.
Gwent Update: Nov 15, 2016: Changed the rarity of Legendary leaders to Epic. Players receive 600 scraps for any non-starter Leader in their collection (to make up the difference in crafting price).
Gwent Update: May 24, 2017: Leaders are now played on the Board in the same manner as other Units.