The odor of sulfur and pumice surrounds a red dragon, whose swept-back horns and spinal frill define its silhouette. Its beaked snout vents smoke at all times, and its eyes dance with flame when it is angry.

A Red Dragon’s Lair

Red dragons lair in high mountains or hills, dwelling in caverns under snow-capped peaks, or within the deep halls of abandoned mines and dwarven strongholds. Caves with volcanic or geothermal activity are the most highly prized red dragon lairs, creating hazards that hinder intruders and letting searing heat and volcanic gases wash over a dragon as it sleeps.

With its hoard well protected deep within the lair, a red dragon spends as much of its time outside the mountain as in it. For a red dragon, the great heights of the world are the throne from which it can look out to survey all it controls—and the wider world it seeks to control.

Lair Actions

On initiative count 20 (losing initiative ties), the dragon takes a lair action to cause one of the following effects; the dragon can’t use the same effect two rounds in a row:

• Magma erupts from a point on the ground the dragon can see within 120 feet of it, creating a 20-foot-high, 5-foot-radius geyser. Each creature in the geyser’s area must make a DC 15 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much damage on a successful one.

• A tremor shakes the lair in a 60-foot radius around the dragon. Each creature other than the dragon on the ground in that area must succeed on a DC 15 Dexterity saving throw or be knocked prone.

• Volcanic gases form a cloud in a 20-foot-radius sphere centered on a point the dragon can see within 120 feet of it. The sphere spreads around corners, and its area is lightly obscured. It lasts until initiative count 20 on the next round. Each creature that starts its turn in the cloud must succeed on a DC 13 Constitution saving throw or be poisoned until the end of its turn. While poisoned in this way, a creature is incapacitated.

Regional Effects

The region containing a legendary red dragon’s lair is warped by the dragon’s magic, which creates one or more of the following effects:

• Small earthquakes are common within 6 miles of the dragon’s lair.

• Water sources within 1 mile of the lair are supernaturally warm and tainted by sulfur.

• Rocky fissures within 1 mile of the dragon’s lair form portals to the Elemental Plane of Fire, allowing creatures of elemental fire into the world to dwell nearby.