Adult Black Dragon
Huge Dragon, chaotic evil
11,500 XP
Special Abilities
Amphibious
The dragon can breathe air and water.
Legendary Resistance (3/Day)
If the dragon fails a saving throw, it can choose to succeed instead.
Actions
Multiattack
The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.
Bite
Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 4 (1d8) acid damage.
Claw
Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.
Tail
Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage.
Frightful Presence
Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 16 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.
Acid Breath (Recharge 5-6)
The dragon exhales acid in a 60-foot line that is 5 feet wide. Each creature in that line must make a DC 18 Dexterity saving throw, taking 54 (12d8) acid damage on a failed save, or half as much damage on a successful one.
Legendary Actions
Detect
The dragon makes a Wisdom (Perception) check.
Tail Attack
The dragon makes a tail attack.
Wing Attack (Costs 2 Actions)
The dragon beats its wings. Each creature within 10 ft. of the dragon must succeed on a DC 19 Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.
Quick Reference
Running This Encounter
An Adult Black Dragon is a devastating foe that demands respect and tactical planning from adventurers. Use its legendary actions to control the battlefield, forcing the party to make difficult choices about positioning and resource management. The dragon should leverage its acidic breath weapon in confined spaces where the party cannot easily escape, and use its intelligence to target spellcasters and healers first. Consider environmental hazards like swamps, acid pools, or collapsing terrain that synergize with the dragon's natural habitat and abilities.
Combat Tactics
The Adult Black Dragon prioritizes using its acid breath weapon (15d8 damage, 90-foot line) to damage multiple enemies at once, then uses Multiattack to focus fire on isolated or weakened party members. It will use its legendary actions to move away from melee threats and maintain distance, relying on its flying speed and AC 19 to minimize incoming damage while maximizing its own output.
Environment & Setting
Adult Black Dragons thrive in acidic swamps, flooded ruins, or subterranean caverns with sulfurous pools and mist. These environments provide cover for the dragon while restricting the party's mobility and escape routes.