Dismal Mist

You cause thick, highly acidic mist to permeate the air in the area for the duration. The area is heavily obscured and is difficult terrain. Sounds within the area are garbled, echoing, and mixed with random hissing noises, making it difficult to orient or communicate by sound. Each construct or creature that attempts to move through the mist must make an Intelligence ability check or its movement is reduced by 10 until it exits the mist. A creature can take the dash action to move through the mist without making the ability check, so long as its movement ends outside the mist area.

A creature, construct, or object that isn’t being worn or carried that starts its turn within the mist or enters it for the first time on a turn must make a Constitution saving throw or take 2d8 points of acid damage, or half as much damage on a successful save. 

 A moderate wind (at least 10 miles per hour) disperses the mist after 4 rounds. A strong wind (at least 20 miles per hour) disperses it after 1 round.

At Higher Levels: When the spell is cast using a fourth level slot or above, the radius of the sphere increases by 10' per spell level above third.