Studied Target: A slayer can study an opponent he can see as a move action. The slayer then gains a +1 bonus on Bluff, Knowledge, Perception, Sense Motive, and Survival checks attempted against that opponent, and a +1 bonus on weapon attack and damage rolls against it. The DCs of slayer class abilities against that opponent increase by 1. A slayer can only maintain these bonuses against one opponent at a time; these bonuses remain in effect until either the opponent is dead or the slayer studies a new target.
If a slayer deals sneak attack damage to a target, he can study that target as an immediate action, allowing him to apply his studied target bonuses against that target (including to the normal weapon damage roll).
At 5th, 10th, 15th, and 20th levels, the bonuses on weapon attack rolls, damage rolls, and skill checks and to slayer DCs against a studied target increase by 1. In addition, at each such interval, the slayer is able to maintain these bonuses against an additional studied target at the same time. The slayer may discard this connection to a studied target as a free action, allowing him to study another target in its place.
At 7th level, a slayer can study an opponent as a move or swift action.
