The Ezrin Quale Trilogy

4th-level evocation

• Casting Time: 1 action
• Range: 300 feet
• Components: V, S, M (a die)
• Duration: Instantaneous
• Classes: Druid, Sorcerer, Wizard

A hail of dice pounds to the ground in a 20-foot-radius, 40-foot-high cylinder centered on a point within range. Each creature in the cylinder must make a Dexterity saving throw. A creature takes 1d4 piercing damage and 1d6+1d8+1d12 bludgeoning damage on a failed save, or half as much damage on a successful one. The dice turn the area of effect into difficult terrain until the end of your next turn, after which they disappear.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the bludgeoning damage increases by 1d8 for each slot level above 4th.

Ezrin's Notes

Mis-spelling of Ice Storm.
If you don't think dice would make the terrain difficult, you've never stepped on a four-sided die.