Out With the Old
Plane of Magma
Optional Rule: Volcanic Activity
All of the plane of magma is unbearably hot, imposing all of the difficultues of extreme heat (see DMG p. 110).. The plane of presents other challenges, however, including constant seismic activity. Each hour, there is a 5% chance of a tremor lasting 1d12 rounds in a given area. This functions as the Earthquake spell. Anywhere NPCs have settles is assumed to be geologically stable and less prone to these quakes.