In their grim and blood-spattered lairs, necromancers experiment with skeletal remains the way chefs tinker with recipes. Many wizards produce variations on the animated skeleton, and undead legions boast their own skeletal officers, specialists, and fearsome elite soldiers.

The following magic items have long lain hidden in subterranean vaults or monster lairs. Many of these items allow adventurers to better traverse or survive jaunts in underground locations; others appear in the dungeon adventures in Dungeon Delver's Guide.

• See the magic items.

Catacombs, barrows, and graveyards are frequently the realms of the undead—although living necromancers and sinister priests may also frequent them. Unlike most other types of dungeon, a tomb has little need for bedrooms, kitchens, and the other requirements of the living.

Tiers. Tombs are common adventuring locations at any tier. While low-level tombs feature skeletons and ghouls, others are home to mighty vampires, dread knights, and dragon liches.

Sand-choked shrines to ancient gods, abandoned abbeys, and cultists’ crypts are built as places of worship and havens for the faithful, but are also designed to guard against profane intruders. A temple usually contains barracks, living areas, and well-defended sacred spaces.

Tiers. Temples range from catacombs at tier 0 to vast, underground cathedrals at higher tiers, with tiers 0 to 2 being the most common.

The typical sewers beneath fantasy cities are magnificent public works from a bygone age. A mishmash of deserted concourses, covered riverways, claustrophobic tunnels, and buried ruins, they are a royal road for thieves, monsters, and adventurers alike.

Tiers. Sewers are rarely tier 3 or 4. Below the sewers, deeper and more dangerous areas are usually ruins, tombs, or other locations.

A weathered castle, a haunted palace, an abandoned labyrinth—any of these constructions may fall into ruin. A ruin is distinct from other dungeons in that it no longer serves a particular purpose. It may be inhabited piecemeal by different groups, but no one ruler or gang controls more than a fraction of it .

Tiers. Ruins can be any tier, with older and more remote ruins tending to house stronger monsters.

Almost every sapient species digs something they want out of the earth. Dwarves dig for adamantine, shadow elves for mithral and dark iron, grimlocks for copper, and everyone mines for iron, gold, salt, and precious stones. When metal and ore are abundant, mines are busy places, but once the supply of that material dwindles, they become eerie, crumbling labyrinths in the lightless depths of the world.

Great war mage colleges, secluded wizard’s towers, and alchemists’ workrooms are all examples of laboratories. Laboratories are places of research and typically include unique magical and alchemical effects that can’t be found anywhere else. In addition to living spaces, a laboratory requires workrooms and libraries.

Tiers. While laboratory inhabitants often include students and apprentices, the masters of large laboratories are commonly tier 3 or 4.