Terra Fossa

Name	Terra Fossa
Cooldown	at-will
Action	standard
Special	DC 15+
Power	terra
Class	arcanist
Category	Control, Shaping

At-will, standard action, DC 15+; the ground opens beneath a targeted 10-foot-square area within 60 feet, creating a pit up to 20 feet deep. Creatures in the area must make a Dexterity save or fall into the pit, taking normal falling damage. The pit's walls are rough stone—climbable with a DC 12 Athletics check. The pit is permanent.

DC +2: increase the pit depth by 10 feet (stackable).
DC +2: increase the area to a 20-foot square.
DC +4: the pit walls are smooth and slick (DC 20 Athletics to climb).
DC +4: the pit closes after 1 round, trapping creatures inside (they can hear and breathe through cracks, but are buried until the earth is moved again).