DECELERATE

 Duration: 1 minute You slow the flow of time around a creature. The creature must make a successful Wisdom saving throw or its speed is halved (rounded up to the nearest 5-foot increment). Until the effect ends, the creature’s speed is halved again at the start of each of your turns. For example, a character with a speed of 30 feet fails its saving throw, dropping its speed to 15 feet. At the start of your next turn, the creature’s speed drops to 10 feet, then to 5 feet on the following round. Decelerate can’t reduce a creature’s speed to less than 5 feet. The spell ends after 1 minute or when the target uses its action to make a successful Wisdom saving throw. At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you can affect an additional creature for each slot level above 3rd.