School abjuration [force]; Level sorcerer/wizard 3
Casting Time 1 standard action
Components V, S
Target one touched object weighing no more than 10 lbs.
Duration permanent until discharged (D)
Saving Throw see text; Spell Resistance yes
You trace mystic runes upon a book, map, scroll, or similar object bearing written information. The explosive runes detonate when read, dealing 6d6 points of force damage. Anyone next to the explosive runes (close enough to read them) takes the full damage with no saving throw; any other creature within 10 feet of the explosive runes is entitled to a Reflex save for half damage. The object on which the explosive runes were written also takes full damage (no saving throw).
You and any characters you specifically instruct can read the protected writing without triggering the explosive runes. Likewise, you can remove the explosive runes whenever desired. Another creature can remove them with a successful dispel magic or erase spell, but attempting to dispel or erase the explosive runes and failing to do so triggers the explosion.
Magic traps such as explosive runes are hard to detect and disable. A character with the trapfinding class feature (only) can use Disable Device to thwart explosive runes. The DC to find magic traps using Perception and to disable them is 25 + spell level, or 28 for explosive runes.