This spell creates an invisible mine field that damages all whom cross it.

This mine field lasts 1 hour per level of the spell caster.

The caster can place  five mines {5 ft. by 5 ft. squares} anywhere that are spread around  a 40 ft. diameter area.  When a creature enters a square, it takes  1d2 (+1 per level of the caster) fire damage (save for half).  Any living thing can trigger the trap.

For every level the spell is cast above one creates 5 more squares.