Volcanic Circle - Witch

This spell causes a gout of red-hot lava to well forth from the ground, creating a pool 10 feet across and about 5 feet deep in the round in which the spell is cast. In the next three rounds, lava continues to pour out from the ground, causing the pool to expand 30 feet per round in all directions to a final radius of 100 feet. Any creature that comes into contact with the hot lava suffers 8d10 points of damage. Once the initial casting is completed, the flow cannot be stopped by dispel magic and similar means.

Just like water, lava runs downhill, so if this spell is cast on a slope the pool may only grow at the rate of 5 feet per round on the uphill side while running downhill at the rate of 40 feet per round. Trenches or hillocks can naturally channel the expanding lava pool, possibly creating safe areas or trapping unwary creatures. The caster cannot be harmed by lava she summons, and she can easily walk over its surface or let it flow around her without injury.

After three rounds, the volcanic circle reaches its maximum extent and begins to cool. Each round thereafter, the damage for coming into contact with the molten rock is lessened by 1d10. For example, five rounds after the volcanic circle ceases to grow, a creature attempting to cross the pool would only suffer 3d10 points of damage. The lava remains as a permanent area of black volcanic rock over the ground, averaging five feet in thickness.

The material component is a shard of obsidian.