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: +14 to hit, reach 15 ft., one target. Hit: (2d10 + 6) piercing damage.   Claw. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: (2d8 + 6) slashing damage. If the target is a Huge or smaller creature, it is grappled (escape DC 24 (10+Athletics)) and is restrained until this grapple ends. The greatwyrm can only have one creature grappled this way at a time.   Tail. Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: (2d10 + 6) bludgeoning damage. If the target is a creature, it must make a DC 22 (8 +Prof + Str) Strength saving throw or be knocked prone   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 24 (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.   Blade Form (Recharge 6). The dragon transforms into a medium sized (8ft tall, 1ft long, 1/10nth of a millimeter wide) ethereal blade, this blade can pass through other creature's spaces but not objects. The dragon can then move up to 150ft without provoking attacks of opportunity and once the dragons stops moving it returns to it's true form. Any creature the blade moves through takes 31 (4d10+Dex) points of magical slashing damage.   Cold Breath (Recharge 5-6). The dragon exhales an icy blast in a 300-foot cone. Each creature in that area must make a DC 22 (8 + Prof + Str) Constitution saving throw, taking 94 (17d10) cold damage on a failed save, or half as much damage on a successful one.   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.

Legendary Actions

The greatwyrm 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 greatwyrm regains spent legendary actions at the start of their turn.   Detect. The dragon makes a Wisdom (Perception) check.   Attack. The dragon makes a claw or tail attack.   Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 30 ft. of the dragon must succeed on a DC 26 (8 + Prof + Str) Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.   Teleport. The dragon teleport to a point it can see within 100ft of itself.  

Mythic Actions

If the greatwyrm's Draconic Awakening trait has activated in the last hour, it can use the options below as legendary actions.   Bite. The greatwyrm makes a bite attack.   Shattering Roar (Costs 2 Actions). The greatwyrm unleashes a magical roar. Each creature in a 120-foot-radius sphere centered on the greatwyrm must succeed on a DC 24 (8 + Prof + Cha) Constitution saving throw or take 19 (3d12) thunder damage and be incapacitated until the end of its next turn.   Blade Form (Costs 3 Actions). The greatwyrm uses its Blade Form action.

Lair Actions

On initiative count 20 (losing initiative ties), the dragon takes a lair action to cause one of the following effects:  

• The dragon creates fog as if it had cast the fog cloud spell. The fog lasts until initiative count 20 on the next round.
• A blisteringly cold wind blows through the lair near the dragon. Each creature within 120 feet of the dragon must succeed on a DC 15 Constitution saving throw or take 5 (1d10) cold damage. Gases and vapors are dispersed by the wind, and unprotected flames are extinguished. Protected flames, such as lanterns, have a 50 percent chance of being extinguished.

Silver dragons dwell among the clouds, making their lairs on secluded cold mountain peaks. Though many are comfortable in natural cavern complexes or abandoned mines, silver dragons covet the lost outposts of humanoid civilization. An abandoned mountaintop citadel or a remote tower raised by a long-dead wizard is the sort of lair that every silver dragon dreams of.

Regional Effects

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

• Once per day, the dragon can alter the weather in a 6-mile radius centered on its lair. The dragon doesn’t need to be outdoors; otherwise the effect is identical to the control weather spell.
• Within 1 mile of the lair, winds buoy non-evil creatures that fall due to no act of the dragon’s or its allies. Such creatures descend at a rate of 60 feet per round and take no falling damage.
• Given days or longer to work, the dragon can make clouds and fog within its lair as solid as stone, forming structures and other objects as it wishes.

  If the dragon dies, changed weather reverts to normal, as described in the spell, and the other effects fade in 1d10 days.