The Primordial Age

In the Primordial Age we lay down some fundamental shapes around which your dungeon will grow.

Setup
Take a blank sheet of paper to be your dungeon map. Draw a rough line across the page the long way, a bit less than two inches from the edge. This is the ground surface. Everything in the narrow area is aboveground; everything below it is underground.

In pencil, write the numbers 1-6 down each narrow side of the page evenly spaced in the underground area.

Roll a d8 on top of the dungeon map. If the die lands off the page, re-roll it so it lands on the page. Consult the appropriate entry in the Primordial Events table for instructions. Repeat this process three times.

Underground River
If an underground river touches the surface, it ends in a lake.