Rune of Blasting

Evocation [force]
Tier: 2
Components: Rune
Casting Time: 1 minute
Range: Touch
Target: Object or surface bearing the rune
Duration: Permanent until discharged
Saving Throw: Reflex half
You speak the word, and hurl the little stone down the hallway, shielding your eyes from the blast.

Once wakened, this rune explodes when it takes damage or suffers a hard impact. The explosion deals 3d6 bludgeoning damage and takes the shape of a 10' cube. If the blast is centered on a square (and not an intersection), roll 1d4 to see which way the blast radiates. If a target takes damage from multiple blast runes simultaneously, each rune after the first only deals 1d6 damage (no save).

If you take damage while holding a wakened blast rune, it has a 50% chance to detonate.

Dwarf war wizards often mark their crossbow bolts with blast runes.

Runic Power:
The explosion deals 6d6 damage, and the rune is even more sensitive. An overcharged blast rune will detonate immediately if fired from a bow or crossbow, dropped from waist height, or if you pat your pocket a little too hard.