A frigid globe of cold energy streaks from your fingertips to a point of your choice within range, where it explodes in a 20m radius sphere.

Each creature within the area must make a Constitution saving throw, taking 10d6 Ice damage and potentially becoming

Brittle

Critical Success (+10). The target is unaffected.
Success. The target takes half damage.
Failure. The target takes full damage and receives 1 level of Brittle for 2 rounds.
Critical Failure (–10). The target takes 1.5× damage, and receives 2 levels of Brittle for 2 rounds.

If the globe strikes a body of water or a liquid that is principally water (not including water-based creatures), it freezes the liquid to a depth of 15cm over an area 10m square. This ice lasts for 1 minute. Creatures that were swimming on the surface of frozen water are trapped in the ice. A trapped creature can use an action to make a Strength check against your spell save DC to break free.

You can refrain from firing the globe after completing the spell, if you wish. A small globe about the size of a sling stone, cool to the touch, appears in your hand. At any time, you or a creature you give the globe to can throw the globe (to a range of 8m) or hurl it with a sling (to the sling's range that would not provide Disadvantage). It shatters on impact, with the same effect as the normal casting of the spell. You can also set the globe down without shattering it. After 1 minute, if the globe hasn’t already shattered, it explodes.

At Higher Levels: Increase the damage by 1d6 for each spell level increase.