Virulent Web

You conjure a mass of thick, sticky webbing at a point you can see within range. The webs erupt in a 20-foot cube at that point. The webs are difficult terrain and lightly obscure their area.

Each creature in a 20-foot-radius square centered on the point you chose must make a Dexterity saving throw. On a failed save, the creature takes 6d6 poison damage, becomes restrained by the webs, and is poisoned for as long as it remains restrained in this way. On a successful save, a creature takes half as much damage and isn't restrained or poisoned.

A restrained creature can use its action to make a Strength check against your spell save DC. If successful, the creature is no longer restrained. At the end of each of its turns, an affected target can remake the saving throw, ending the effect on itself with a success. If the save fails, the target takes 2d6 poison damage.

The webs are flammable. Any 5-foot cube of webs exposed to fire burns away in 1 round, dealing 2d4 fire damage to any creature that starts its turn in the fire.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 and the cube increases by 5 feet for each slot level above 3rd.