Raw Abyssal energy sometimes seeps up through the ground, forming misshapen, puckered mounds of earth measuring from 6 inches to several feet across. At random intervals these mounds explode, venting geysers of energy into the air. These mounds also explode if they’re disturbed (stepped upon, prodded, damaged with a spell, and so forth).
A successful DC 15 Acrobatics check is required to move through a square infested with dormant Abyssal geysers without setting one off.
Once a geyser erupts, it explodes in a 30-foot-radius burst, dealing 4d6 points of energy damage to all creatures in that area (Reflex DC 15 for half ). Determine the damage’s energy type (acid, cold, electricity, fire, or sonic) randomly. A successful DC 20 Perception check enables a character to notice an Abyssal geyser’s dangers before triggering it accidentally. Once a geyser is triggered, it generally won’t trigger again, but some can quickly rebuild their potential and erupt multiple times. Some geysers are more powerful. Each 2d6 points of damage added to a geyser’s damage increases its burst radius by 5 feet, its Reflex save DC by 1, and its CR by 1, to a maximum of 20d6 points of energy damage (Reflex DC 23 for half ) in a 60-foot radius (a CR 10 Abyssal geyser).
Pathfinder Campaign Setting: The Worldwound © 2013, Paizo Publishing, LLC; Authors: James Jacobs, Jonathan Keith, Jason Nelson, Todd Stewart, and Tanith Tyrr.