Eruption

A 10ft circle of magma erupts form the earth dealing [roll]6d10[/roll] and launching them [roll]1d8[/roll]x10 in to the air, dropping [roll]1d6[/roll] tiles from their original position a random direction and taking falling damage as normal.
If some obstacle prevents the target creature from reaching its expelled height, it takes 1d6 points of damage for every 10 feet of movement it was unable to complete, so that a creature hurled 50 feet up in a room with a 20-foot ceiling would take 3d6 points of damage from the impact, then take 2d6 points of damage when it falls back to the ground.