• Armor Class: 22 • Hit Points: 481 (26d20+208) • Speed: 40 ft., burrow 40 ft., fly 80 ft.
• Saving Throws:
Dex +7, Con +15, Wis +10, Cha +12 • Skills:
Perception +17, Stealth +7 • Senses:
blindsight 60 ft., darkvision 120 ft. • Languages:
Common, Draconic • Challenge:
23 (50000 XP) • Environments:
• 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 plus 11 (2d10) lightning 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.
• Lightning Breath (Recharge 5-6): 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.
The ancient blue dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature's turn. The ancient blue dragon regains spent legendary actions at the start of its turn.
• 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.