Chains of Ice

Choose up to 2 targets within range. Each target must make a Strength saving throw. On a success, the target takes no damage and is not restrained. On a failed save, the target takes 1d6 cold damage and 1d6 bludgeoning damage and is restrained. As long as you maintain concentration, the target takes an additional 1d6 cold damage at the start of their turn, and as an action on your turn, you may tighten the chains and deal an additional d6 of bludgeoning damage. The target can use an action on their turn to break free using a Strength (athletics) check against your spell save DC. Alternatively, a creature can be broken free by attacking the chains. The chains have an AC equal to your spell save DC and 10 hit points. 

If you lose concentration, the chains remain, still dealing the cold damage at the start of the target’s turn and restraining them until they are broken free, however you can no longer use an action to deal additional bludgeoning damage. Every turn the chains remain without concentration, they melt a little dropping the DC by 1 and dealing 1 point of damage to the chains, unless they are in a place where the ambient temperature is freezing or below. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, you may target 1 additional creature, the initial bludgeoning damage and the bludgeoning damage from tightening the chains as an action increases by 1d6, and the chains gain an additional 10 hit points per spell level above 1st.