Field of Icy Razors

(Spell Compendium, page 90, DnD 3.5)

Evocation

Level: ; Sorcerer/Wizard 8
Components: V, S
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Target: One creature/level, no two of which are more than 60 ft. apart
Duration: Instantaneous plus 1 round/level; see text
Saving Throw: Reflex partial
Spell Resistance: Yes

Your breath becomes cold and frosty as you intone this spell, and blue-white crystals erupt from the soil, chill air swirling around their needle-sharp tips.

Razor-sharp ice crystals surround the targets. Each target takes 1d6 points of damage per caster level (maximum 20d6); half of this damage is cold damage, and half is slashing. In addition, each target's speed is reduced by 20 feet for 1 round per caster level. Creatures that succeed on Reflex saving throws take half damage and their movement is unaffected.

Focus: A silver suriken worth 50 gp that looks like a snowflake.