Extreme Gravity

A planet where the gravity is at least five times as strong as standard gravity is extremely dangerous to most creatures. In addition to the limitations of high gravity (see below), a creature in this environment takes an amount of nonlethal bludgeoning damage per round (at least 1d6, but potentially more, depending on the intensity of the gravity). Once a character takes sufficient nonlethal damage to be reduced to 0 Hit Points, any further damage from extreme gravity is lethal bludgeoning damage.