Combat Expertise -1/+2 Bonus to AC in exchange for an equal penalty to attack.
Elf Blood Half-elves count as both elves and humans for any effect related to race.
Elven Immunities - Sleep You are immune to magic sleep effects.
Low-Light Vision See twice as far as a human in dim light, distinguishing color and detail.
Sneak Attack +2d6 Attacks deal extra dam if flank foe or if foe is flat-footed.
Studied Target +2 (move action, 2 at a time) (Ex) Study foe as a Move action, gain +2 to att/dam & some skills vs. them.
Track +3 Add the listed bonus to Survival checks made to track.
Trap Sense +2 (Ex) +2 bonus on reflex saves and AC against traps.
Trapfinding +3 Gain a bonus to find or disable traps, including magical ones.
Two-Weapon Feint Forgo first melee attack to feint