The Reign Of Winter
Challenge (Ex): Once per day, a cavalier can challenge a foe to combat. As a swift action, the cavalier chooses one target within sight to challenge. The cavalier’s melee attacks deal extra damage whenever the attacks are made against the target of his challenge. This extra damage is equal to the cavalier’s level. The cavalier can use this ability once per day at 1st level, plus one additional time per day for every three levels beyond 1st, to a maximum of seven times per day at 19th level.
Challenging a foe requires much of the cavalier’s concentration. The cavalier takes a –2 penalty to his Armor Class, except against attacks made by the target of his challenge.
The challenge remains in effect until the target is dead or unconscious or until the combat ends. Each cavalier’s challenge also includes another effect which is listed in the section describing the cavalier’s order.