Hardened Surface

4th-level transmutation

Classes: cleric, sorcerer, wizard

Casting Time: 1 minute

Range: Touch

Components: V, S

Duration: Until dispelled

You cause the surface of a permanent structure within your stronghold, such as a wall, door, or statue, to become harder and more durable, up to a 10-foot square surface, increasing its damage threshold by 5 and adding 10 hit points to each 5-foot square you affect. The hardened surface extends 1 foot deep into the structure. If you wish to harden the entire thickness of an object that is thicker than 1 foot, you can cast hardened surface repeatedly in the same area, with each casting increasing its depth by 1 foot. While this spell increases the surface’s resistance to physical damage, it does not alter the fundamental characteristics of the material that makes up the structure. A wall of paper or straw still can be set aflame, a structure of snow or ice can melt, and so on.

This spell also can be used to harden structures made of snow and ice.

If you establish a new stronghold, any hardened surface spells you cast in your former stronghold begin to fade, ending after one day per caster level passes.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage threshold increases by 1 and the hit points for each 5-foot section increase by 2.