Insight +10, Perception +17, Persuasion +16, Stealth +9
+2
Blindsight 60 ft, Darkvision 120 ft
Common, Draconic
Fire
Traits
Amphibious
The ancient gold dragon can breathe air and water.
Legendary Resistance
3/day (4/day in lair). If the ancient gold dragon fails a saving throw, it can choose to succeed instead.
Actions
Multiattack
The dragon makes three Rend attacks. It can replace one attack with Spellcasting to cast Guiding Bolt (level 4 version), or with Weakening Breath.
Rend
Melee Weapon Attack: +17 to hit, reach 15 ft.. Hit: 19 (2d8 + 10) slashing plus 9 (2d8) fire damage.
Fire Breath
Recharge 5–6. Dexterity Saving Throw: DC 24, each creature in a 90-foot Cone.
Failure: 71 (13d10) fire damage.
Success: Half damage.
Spellcasting
1 use per day; 2 uses per day. The ancient gold dragon casts one of the following spells, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 24):
At Will: Detect Magic, Guiding Bolt (level 4 version), Shapechange (Beast or Humanoid form only, no Temporary Hit Points gained from the spell, and no Concentration or Temporary Hit Points required to maintain the spell)
1/Day Each: Flame Strike (level 6 version), Word of Recall, Zone of Truth
Weakening Breath
Strength Saving Throw: DC 24, each creature that isn't currently affected by this breath in a 90-foot Cone.
Failure: The target has Disadvantage on Strength-based D20 Tests and subtracts 5 (1d10) from its damage rolls. It repeats the save at the end of each of its turns, ending the effect on itself on a success. After 1 minute, it succeeds automatically.
Legendary Actions
3 legendary actions (4 in its lair). Only one legendary action can be used at a time and only at the end of another creature's turn. This creature regains spent legendary actions at the start of its turn.
Banish
Charisma Saving Throw: DC 24, one creature the ancient gold dragon can see within 120 feet.
Failure: 24 (7d6) force damage, and the target has the Incapacitated condition and is transported to a harmless demiplane until the start of the ancient gold dragon's next turn, at which point it reappears in an unoccupied space of the ancient gold dragon's choice within 120 feet of the ancient gold dragon.
Failure or Success: The ancient gold dragon can't take this action again until the start of its next turn.
Guiding Light
The ancient gold dragon uses Spellcasting to cast Guiding Bolt (level 2 version).
Pounce
The ancient gold dragon moves up to half its Speed, and it makes one Rend attack.
Prepared Spells
Guiding Bolt, Detect Magic, Guiding Bolt, Shapechange, Flame Strike, Zone Of Truth, Word Of Recall