You ready yourself for an approaching enemy, deftly maneuvering to a better position and striking before your foe strikes you.

Encounter   ✦     Weapon
Immediate Reaction      Melee weapon

Trigger: An enemy enters a square adjacent to you

Effect: Before the attack, you shift 1 square.

Target: The triggering enemy

Attack: Strength vs. AC

Hit: 2[W] + Strength modifier damage.

Published in Player's Handbook 2, page(s) 22.