D&D4 Wiki
Icy terrain
wizard attack 1

area burst 1 within 10 squares

Target: each creature in the area of effect

Attack: Intelligence vs. Reflex

Hit: "1d6 + Intelligence modifier cold damage, and the target falls prone."

Effect: "The burst creates a zone that lasts until the end of your next turn or until you end it as a minor action. The ground of the zone is difficult terrain. The power's area is difficult terrain until the end of your next turn. You can end this effect as a minor action."[PH:160][Dr401:54][U :12/2011]

Icy terrain is an encounter power available to wizards at 1st level.

The "Class Compendium: The Arcanist" article in Dragon 401 added the evocation and zone keywords to icy terrain. The December 2011 update finalized these changes.