Blastbones

This spell allows the caster to shatter exposed bones in a violent explosion. The bones can be part of a simple undead skeleton or partial zombie, or inanimate skeletal remains, which can be any number of small, disconnected pieces. The bones of creatures with more than 4 Hit Dice or levels are immune to this spell.

The spell can be cast to take effect immediately, or set to be triggered at any later time, at conditions governed by a verbal summary identical to that used in a magic mouth spell.

If acting immediately, the spell causes a skeleton, pile of bones, or the like to explode in a blast that affects a 10-foot radius spherical blast area. Those in the area are allowed a saving throw vs. spells for half damage; if it fails, they take 2d4 points of damage from bone shards. If the skeleton is undead, it is destroyed in the explosion.

Undead normally receive a saving throw against a blastbones spell; if the save is successful, the spell creates only a small explosive puff, inflicting 1d4+1 points of damage. If a delayed blastbones spell is cast on remains before they are animated as undead, no saving throws by the undead are allowed; the animation does not impair the future operation of the spell.

If set as a trap, the blastbones damage can be augmented by other material placed to serve as shrapnel. One common use for this spell involves a partial zombie, set as a guardian. When it is attacked for a total of 6 points or more of damage, it explodes in shards of rotting flesh, bones, and nails (placed inside it before animation). Any creature within 15 feet is hit by 1d12 nails; each nail does 1 hit point damage, and those within 10 feet take 2d4 points of damage from the bone shards as well. Those from 10 to 20 feet distant mast make two successful saving throws vs. paralyzation to escape damage: if one check succeeds, only 1d3 nails strike; if both checks fail, 1d6 nails strike.

The material components for this spell are a drop of water, a fleck of dust, a pinch of ash, and the bones to be affected.

Notes: Uncommon for necromancers; otherwise very rare. (Updated from DRAGON Magazine.)