You create several hidden mines throughout the area that explode when stepped on. Choose up to 6 unoccupied squares within range. A mine appears in each chosen square, visible only to you and your allies. A mine can't be targeted and isn't affected by area effects, but if it hasn't been triggered by the end of the spell's duration, it dissipates harmlessly. A creature that can see Invisible creatures and objects can see the mines. A creature can also attempt a Perception check against your spell DC to Seek to find an invisible mine.
A creature who enters a square with an invisible mine triggers it, causing an explosion that deals 3d6 fire damage and 3d6 piercing damage (basic Reflex save) to the creature and every creature in a 5-foot emanation from the mine's square.
Heightened (+1) The fire damage and piercing damage dealt by a mine each increase by 1d6.
Traits
Effects with the fire trait deal fire damage, or either conjure or manipulate fire. Those that manipulate fire have no effect in an area without fire. Creatures with this trait consist primarily of fire or have a connection to magical fire.
Effects and magic items with this trait involve false sensory stimuli.
You must physically manipulate an item or make gestures to use an action with this trait. Creatures without a suitable appendage can't perform actions with this trait. Manipulate actions often trigger reactions.
A spell with the subtle trait can be cast without incantations and doesn't have obvious manifestations.