This powerful spell works only upon stone, masonry, and mortar. The priest must touch the construction to be affected continuously during casting, and then make a saving throw vs. petrifaction. If it fails, the spell does too, and the priest immediately sustains 1(16 points of damage. If it succeeds, the wall is weakened. A falling wall spell affects such constructions as if weather had worked on them for long periods. It causes mortar to crumble, drives stones apart, and even causes walls to collapse. The precise effects of this spell are adjudicated by the DM in accordance with the prior condition of the wall and the situation. (For example, weakening a culvert through which water is rushing is quite likely to cause parts of it to break off and be carried away by the flow, enlarging the opening, but trying to break a hole in a strong, thick, unbroken, and fairly new wall is probably hopeless.)
The caster can affect a maximum area of 5 cubic feet per level, but the extent of this is up to the priest (it can be along a surface or directed into a narrow cylinder sent straight through a wall). Natural rock formations, however fragile or unstable, are not affected by this magic, only artificial constructions. Carvings that leave a solid piece of rock as their result are also immune to the effects
that are aided by spells or props before or during the operation of the spell are fairly likely to withstand the spell, but small stone pieces are easily shattered by use of this spell.
Notes: Granted by the woodland god Silvanus of the Forgotten Realms setting. This spell is found only in a few exceptionally rare tomes.