Breath Weapon

You can use your action to exhale destructive energy. Your draconic ancestry determines the size, shape, and damage type of the exhalation. Each creature in the area must make a saving throw (DC = 8 + your Constitution modifier + your proficiency bonus), taking 2d6 damage on a failed save, half as much on a success. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level. After you use your breath weapon, you can't use it again until you complete a short or long rest.

As an action, you can exhale destructive energy in a 15-foot cone (or a 5-by-30-foot line for lightning ancestries). Each creature in the area makes a Dexterity saving throw (DC 8 + your Constitution modifier + your proficiency bonus), taking 2d10 damage of the associated type on a failed save, half as much on a success. The damage increases at higher levels. You can use this trait a number of times equal to your proficiency bonus, regaining all expended uses when you finish a Long Rest.