Boss is an entity rank for Adversaries and Opponents. In terms of scenario design, a boss is worth four PCs of equal level.
Bosses start with a +2 in each Stat Track.
Bosses each have a deck of cards and draw and discard according to the standard rules. They the normal base Hand Limit; however, their default +2 Mind means they start with a bonus (and thus an extra card in the first round). Bosses may include special cards in their deck that are only available to them.
Bosses take three turns per round; as such, they roll Initiative three times at the beginning of the scenario. However, a boss can only perform a Move during one of these three turns each round unless otherwise specified.