Chance to hit, then average damage per attack once misses and critical hits are counted.
Attack
AC 12
AC 14
AC 15
AC 16
AC 18
AC 20
Rend (+17)
95% 27.5 dmg
95% 27.5 dmg
95% 27.5 dmg
95% 27.5 dmg
95% 27.5 dmg
90% 26.1 dmg
Full turn (3 attacks)
82.5 dmg
82.5 dmg
82.5 dmg
82.5 dmg
82.5 dmg
78.3 dmg
Ancient Gold Dragon hit points
The stat block uses the average, 546. Rolled, 28d20 + 252 lands anywhere from 280 to 812.
280chance of each total for 28d20 + 252812
Hit points
Chance
413 or more
>99%
546 or more
51%
679 or more
<1%
759 or more
<1%
Traits
Amphibious. The dragon can breathe air and water.
Legendary Resistance. If the 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 a use of (A) Spellcasting to cast Guiding Bolt (level 4 version) or (B) Weakening Breath.
Rend. Melee Attack Roll: +17 to hit, reach 15 ft. Hit: 19 () Slashing damage plus 9 () Fire damage.
Fire Breath. Dexterity Saving Throw: DC 24, each creature in a 90-foot Cone. Failure: 71 () Fire damage. Success: Half damage.
Spellcasting. The dragon casts one of the following spells, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 24, +16 to hit with spell attacks):
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 () 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
Banish. Charisma Saving Throw: DC 24, one creature the dragon can see within 120 feet. Failure: 24 () Force damage, and the target has the Incapacitated condition and is transported to a harmless demiplane until the start of the dragon’s next turn, at which point it reappears in an unoccupied space of the dragon’s choice within 120 feet of the dragon. Failure or Success: The dragon can’t take this action again until the start of its next turn.
Guiding Light. The dragon uses Spellcasting to cast Guiding Bolt (level 4 version).
Pounce. The dragon moves up to half its Speed, and it makes one Rend attack.