Wall of Acid

You create a wall of acid on the ground at a point you can see within range. The acid appears transparent and flows similar to water. A creature can identify the acidic nature of the wall through a successful nature check against your spell DC. This check is made automatically by any creature within 10 feet of the wall that can see it without requiring an action. You can make the wall up to 30 feet long, 10 feet high, and 1 foot thick, or you can make a ringed wall up to 20 feet in diameter, 20 feet high, and 1 foot thick. The wall vanishes when the spell ends. The wall’s space is difficult terrain.

Any non-magical ranged weapon attack that enters the wall’s space automatically fails as the ammunition is dissolved by the wall, revealing the wall's nature to any that can see it. Magical ranged weapon attacks that enter the wall's space are made at disadvantage. Spells that deal cold damage that pass through the wall cause the area of the wall they pass through to freeze solid (at least a 5-foot-square section is frozen). Each 5-foot-square frozen section has AC 5 and 15 hit points. Reducing a frozen section to 0 hit points destroys it. When a section is destroyed, the wall’s water doesn’t fill it.

A creature that starts its turn in the walls space or enters its space for the first time on its turn must make a constitution saving throw. On a failed save, it takes 5d8 acid damage or half as much on a success. A creature that ends its turn in the wall's space takes 5d8 acid damage.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th.