Requirement: You must be adjacent to the door.
Attack: Melee 1 (one creature adjacent to the door); +9 vs. Reflex
Hit: 2d6 + 7 damage, and the target is immobilized (save ends) and falls prone.
Miss: The falling door pushes the target up to 4 squares.
Published in Madness at Gardmore Abbey, page(s) 4-3.