Guardian Hammer

This spell creates a guardian hammer: an invisible, hammer-shaped field of force activated when a guarded door or other area is disturbed.

When activated, it charges through the air to strike the nearest living thing to the disturbed area or any being in the area (if there is more than one, determine the target randomly). A guardian hammer strikes only once, but does not miss. When it hits, it appears momentarily as a glowing, translucent hammer and then fades away into nothingness. Its strike does 4d12 damage, and stuns the struck creature for 1d4+1 rounds (no voluntary actions possible). Struck beings must make a successful Strength check to avoid being knocked down, forcing possible item saving throws vs. crushing blow for fragile carried items.

A guardian hammer spell can be destroyed before activation by casting dispel magic on the guarded area or by totally destroying the guarded area without entering it (for example, by disintegration). The latter method destroys all guardian hammer spells attached to an area; the former method destroys only one guardian hammer per dispel magic, if multiple spells exist. Once activated, a guardian hammer can dodge all magical and physical barriers, by way of the Ethereal Plane (phasing in and out) if necessary. It cannot be destroyed or diverted to another target by such means.

The material components for this spell are a drop of sweat or spittle or a tear from the caster, a hair from a dwarven stone mason, and a pebble or lump of ice.