Adaptable. You have a burrow speed or swim speed equal to your walking speed, chosen to match your ancestor. You can breathe both air and water if you have a swim speed.
Damage Immunity. You are immune to the damage type determined by your Draconic Ancestor.
Legendary Resistance (3/day). If you fail a saving throw, you can choose to succeed instead.
Telepathy: If you had any natural telepathic ability (not from equipment or a spell) before transforming, then you retain access to it in this form.
Multiattack. You can use Frightful Presence, one bite and two claw attacks as a single action.
Bite. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 7 (2d6) damage of your Draconic Ancestor's damage type.
Claw. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 15 (2d6 + 8) slashing damage.
Tail. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage.
Breath Weapon (Recharge 5–6). You exhale destruction in your choice of a 60-foot cone, or a 90-foot line that is five feet wide. Each creature in that area must take a Dexterity saving throw (DC 21), taking 66 (12d10) damage on a failed save, or half as much on a success. Damage type is determined by your Draconic Ancestor.
Frightful Presence. Each creature of your choice within 120 feet and aware of you must succeed on a DC 21 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 your Frightful Presence for 24 hours.
You can take 3 legendary actions, choosing from the options below. Only one option can be used at a time and only at the end of another creature's turn. You regain spent Legendary Actions at the start of your turn.
Detect. You make a Wisdom (Perception) check.
Tail Attack. You make one attack with your tail.
Wing Attack (Costs 2 Actions). You beat your wings. Each creature within 10 feet of you must succeed on a DC 22 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone. You can then fly up to half your flying speed.
Description
The Draconic Form can eventually be assumed by a sorceror with Draconic Ancestry, embodying the ancestor from which their power flows. In this form the sorceror is truly terrifying, with strength and durability far beyond any mere mortal.
Lair and Lair Actions
Your Lair
Your Draconic Form's preferred lair is determined by your Draconic Ancestor, and the preferences of your character.
Lair Actions
On initiative count 20 (losing initiative ties), you can take a lair action to cause one of the following effects; you can’t use the same effect two rounds in a row:
- You glimpse the future, gaining advantage on attack rolls, ability checks, and saving throws until the end of the round.
- Suitable terrain features (determined by the DM) that you can see within 120 feet erupt or shift unpredictably. Creatures within 20 feet of any such feature must take a DC 15 Dexterity check. On a failure a creature suffers 21 (6d6) damage of the type determined by your Draconic Ancestor, and their walking speed is halved until the end of their next turn. On a success a creature takes half damage and no movement penalty.
- You choose a point you can see within 120 feet, creating an area of magical darkness or light (appropriate to your Draconic Ancestor's type) with a radius of 30 feet. Creatures within an area of light when it forms must take a DC 17 Constitution save or be blinded for one minute.
Regional Effects
The region containing your lair is warped by its magic, which creates one or more of the following effects:
- The land within 6 miles of the lair takes twice as long as normal to traverse.
- Your enemies find it difficult to rest within 1 mile of your lair – if they take a short rest they regain only half the normal hitpoints, and if they have no points of exhaustion at the end of a long rest they gain one.
- Choose either fog that lightly obscures the area for 6 miles, or your enemies have disadvantage on Stealth checks within 1 mile.
If the you die or revert back, the terrain remains difficult to traverse but other effects will end after 1d10 days.
This stat block is not intended for use as a normal monster, but is an added draconic form for the Draconic Ancestry sorcerer sub-class to transform into.
That said nothing prevents it from being used as a proper monster (and it should function correctly as one) if you just want a CR17* base for building a custom dragon on top of. *CR17 is the rating at which it is balanced, it's listed as CR18 because that's the minimum level at which the draconic sorcerer can use it (as it's tied to the 18th-level sub-class feature).