Endless varieties of mushrooms proliferate in the sunless environs of Underland. Many are especially hazardous to intelligent intruders.

When a party of heroes ventures into a dungeon or the caves of Underland, some of the adventurers may be doing so for the first time. Others are simply returning home. Below are backgrounds suitable for characters native to underground environments.

The following archetypes are excellent choices for use in a campaign in which dungeoneering and subterranean exploration are major themes—but a character with one of these archetypes can hold their own on the surface as well. Some of these archetypes are based on combat and magic traditions developed by underground dwellers; others were invented by treasure hunters and explorers.

This section contains new monsters that are likely to be encountered in dungeons or deep underground. Some of these monsters are referenced in chapter 2, “Random Dungeon Delves” or “3-Page Dungeons,” while others appear nowhere else in this book. In either case, use these monsters as you see fit in your own dungeon adventures.

If you haven’t used a Level Up book before, some of the terms used in these stat blocks, such as the bloodied condition and Maneuver DC, may be new to you; these are pieces of shorthand intended to make monsters easier to run. The terms are explained in this introduction to this book.