An exhausted card is a card that is not currently ready or frightened. The exhausted state is represented by placing an exhausted token on the card; this token is removed if the card becomes readied, frightened or is removed from play.
Exhausted characters cannot use their power to confront Problems or participate in faceoffs (unless they have the Stubborn keyword), but they can still use their power to meet the play requirements of other cards.
A player readies all of their exhausted cards as part of their Ready Phase. Game text can also be used to ready exhausted cards.