Ancient Bronze Dragon
Gargantuan Dragon, lawful good
41,000 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: +16 to hit, reach 15 ft., one target. Hit: 20 (2d10 + 9) piercing damage.
Claw
Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 16 (2d6 + 9) slashing damage.
Tail
Melee Weapon Attack: +16 to hit, reach 20 ft., one target. Hit: 18 (2d8 + 9) 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 20 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.
Breath Weapons (Recharge 5-6)
The dragon uses one of the following breath weapons.
Lightning Breath. The dragon exhales lightning in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 23 Dexterity saving throw, taking 88 (16d10) lightning damage on a failed save, or half as much damage on a successful one.
Repulsion Breath. The dragon exhales repulsion energy in a 30-foot cone. Each creature in that area must succeed on a DC 23 Strength saving throw. On a failed save, the creature is pushed 60 feet away from the dragon.
Change Shape
The dragon magically polymorphs into a humanoid or beast that has a challenge rating no higher than its own, or back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (the dragon's choice).
In a new form, the dragon retains its alignment, hit points, Hit Dice, ability to speak, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form.
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 15 ft. of the dragon must succeed on a DC 24 Dexterity saving throw or take 16 (2d6 + 9) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.
Quick Reference
Running This Encounter
An Ancient Bronze Dragon is a legendary creature requiring careful preparation and pacing. Use its lair actions to control battlefield positioning and force the party into difficult decisions each round. Allow the dragon to use its intelligence tactically—retreating when bloodied, using cover, and leveraging its amphibious nature. Consider having allied creatures or minions present to extend the encounter's duration and prevent the party from focusing all damage on the dragon.
Combat Tactics
The Ancient Bronze Dragon opens combat with devastating area spells like Chain Lightning, then uses its legendary actions to maximize damage output. It focuses fire on full casters and healing clerics while maintaining distance using fly-by attacks and water-based maneuvers. When reduced below half health, it may attempt to flee rather than fight to the death.
Environment & Setting
An ideal setting is a coastal or riverside lair with deep water nearby, allowing the dragon to leverage its swimming speed and amphibious nature. Incorporate high cliff faces, waterfalls, submerged caverns, and stone pillars to create dynamic 3D terrain for both ranged and melee combatants.