Eruption

Choose a point you can see on the ground within range. A fountain of magma erupts in a 20-foot square centered on that point. Each creature in that area when the spell is cast must make a Dexterity saving throw, and a creature must make the save if it ends its turn in the area or if it enters the area for the first time on its turn. A creature takes 2d6 fire damage on a failed save, or half as much damage on a successful one. Additionally, the ground in that area becomes difficult terrain for 1 minute. At the end of this minute, the magma cools and the area is no longer difficult terrain. For 1 minute after cooling, a creature who ends their turn in the area must make a dexterity saving throw or take 1d6 fire damage, or no damage on a successful save.

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