Chains of Ice

Icy chains rapidly form around one creature that you can see within range. The target takes 2d6 Cold damage and its Speed is reduced by 10 feet for the duration. Until the spell ends, you can take a Bonus Action on each of your later turns to deal this damage again if the target is within range and if it has the Restrained condition.

At the start of each of your later turns, if the target has not moved at least 10 feet since your last turn, it has the Restrained for the duration. A Restrained creature can take an action to make a Strength (Athletics) check against your spell save DC. On a success, it loosens the chains and is no longer Restrained by them.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 2.