You create a 30-foot-radius sphere of poisonous, yellow-green fog centred on a point you can see within range.

The fog spreads around corners. It lasts for the duration or until strong wind disperses the fog, ending the spell. The area is heavily obscured.

Creatures that enter the spell’s area for the first time on a turn or ends its turn there must make a Constitution saving throw. The creature takes 6d8 poison damage on a failed save, or half as much damage on a successful one. Creatures are affected even if they hold their breath or don't need to breathe.

The fog moves 10 feet away from you at the start of each of your turns, rolling along the surface of the ground. The vapours, being heavier than air, sink to the lowest level of the land, even pouring down openings.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the damage increases by 1d8 for each slot level above 5th.