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: +13 to hit, reach 10 ft., one target. Hit: (2d10 + 7) piercing damage plus (2d6) necrotic damage.   Claw. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: (2d6 + 7) slashing damage.   Tail. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: (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 16 (8 + Prof + Cha) 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.   Shadow Breath (Recharge 5-6). The dragon exhales fire in a 60-foot cone. Each creature in that area must make a DC 21 (8 + Prof + Str) Dexterity saving throw, taking 63 (18d6) necrotic damage on a failed save, or half as much damage on a successful one. A humanoid reduced to 0 hit points by this damage dies, and an undead shadow rises from its corpse and acts immediately after the dragon in the initiative count. The shadow is under the dragon’s control.   Enraging Roar. The dragon roars as an action, every creature within 120ft that can hear the dragon must make DC 16 (8 + Prof + Cha) becoming Reckless on a failure. A creature who is Reckless must attack recklessly (as per the barbarian ability) and has advantage on physical saving throws but disadvantage on mental saving throws, these creatures can repeat the save at the end of each of their turns ending the effect on success. The dragon can use this action a number of times equal to it's proficiency bonus.   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.ny class features or legendary actions of that form.

Legendary Actions

Adult Red 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. Adult Red Dragon regains spent legendary actions at the start of their turn.   Detect. The dragon makes a Wisdom (Perception) check.   Tail Attack. The dragon makes a tail attack.   Ignite Blood (Costs 2 Actions). If the dragon is damaged it can take this action. The spaces the dragon has occupied or flown over since the start of it's last turn burst in flame as the dragon blood burns, any creature occupying those spaces must make a DC 21 (8 + Prof + Con) Dexterity saving throw, taking 4d6 necrotic damage on a failure or half as much on a success. A creature with Red Dragon Blood on it has to make the save even if it is just adjacent to an effected space, these creature also make the Dexterity saving throw at disadvantage. This fire ignites any flammable object that isn't being worn or carried, a object that has Red Dragon Blood on it is ignites if is adjacent to an effected space.   Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 10 ft. of the dragon must succeed on a DC 21 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.

Lair Actions

On initiative count 20 (losing initiative ties), the dragon takes a lair action to cause one of the following effects; the dragon can’t use the same effect two rounds in a row:  

• A tremor shakes the lair in a 60-foot radius around the dragon. Each creature other than the dragon on the ground in that area must succeed on a DC 15 Dexterity saving throw or be knocked prone.
• The Shadow Dragon summons a swarm of shadowy hands to rise up and attempt to restrain a creature it can see or hear that is standing in dim light or darkness. The creature must succeed on a DC16 Strength saving throw or be Restrained, taking 3d6 necrotic damage at the start of each turn. A creature restrained by these hands can use its action to repeat the Strength saving throw, freeing itself on a success.
• The Shadow Dragon extinguishes all non-magical and magical sources of light within 60ft range. Magical sources of light that are being maintained using concentration magic prompt the caster to make a DC18 concentration saving throw. Non-magical light sources are extinguished until they can be lit again, and magical light sources begin functioning again at the start of the next round.

Regional Effects

The region containing a legendary red dragon’s lair is warped by the dragon’s magic, which creates one or more of the following effects:  

• Small earthquakes are common within 6 miles of the dragon’s lair.
• The sun never rises. The sky remains inky black and the air is cold and lifeless within 1d4 miles of the lair. Colors seem muted and gray.
• Within a mile of the lair, portals to the Shadowfell open and close at random. Roll a d6 every hour, with a portal to the Shadowfell opening on a 4-6. On a 6, creatures native to the Shadowfell emerge from the portal to attack anything nearby. The portal lasts for 1d4 hours before closing.