Fireball Rune 5
Evocation Fire Magical Trap
Stealth: DC 24 (expert)
Description: An invisible rune creates an invisible, spherical magical sensor with a 20-foot radius.
Disable: Thievery DC 22 (expert) to erase the rune without triggering the sensor, or dispel magic (3rd level; counteract DC 20) to counteract the rune
(arcane, evocation, fire) Trigger: A living creature enters the sensor area Effect: The rune detonates a fireball centered on the triggering creature’s square. This is a 3rd-level fireball spell that deals 6d6 fire damage (DC 22 basic Reflex save).
Source: Core Rulebook pg. 524 2.0