Adult Blue Dragon
Huge dragon, lawful evil
Armor Class
19
Hit Points
225 (18d12+108)
Speed
40 ft., burrow 30 ft., fly 80 ft.
STR
25 (+7)
DEX
10 (0)
CON
23 (+6)
INT
16 (+3)
WIS
15 (+2)
CHA
19 (+4)
Damage Immunities
lightning
Senses
blindsight 60 ft., darkvision 120 ft.
Saving Throws
Dex +5, Con +11, Wis +7, Cha +9
Skills
Perception +12, Stealth +5
Languages
Common, Draconic
Challenge
16 (15,000 XP)
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: +12 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 5 (1d10) lightning damage.
Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage.
Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 16 (2d8 + 7) bludgeoning damage.
Frightful Presence. Each creature of the dragon’s choice that is within 120 ft. of the dragon and aware of it must succeed on a DC 17 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 90-foot line that is 5 ft. wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 66 (12d10) lightning damage on a failed save, or half as much damage on a successful one.
Legendary Actions
The adult 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 adult 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 10 ft. of the dragon must succeed on a DC 20 Dexterity saving throw or take 14 (2d6 + 7) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.