The Freeze can be used in combination with Balloons to deal immense damage to buildings and Crown Towers. The Freeze should be cast once the Balloon approaches the Crown Tower, disabling any enemy troops deployed to assist the Crown Tower and the Tower itself. It can also be used in affiliation with the Hog Rider. If executed properly, the Hog Rider can inflict immense damage to the Crown Tower during the Freeze's duration.
It can also be used defensively to stop incoming troops such as the P.E.K.K.A., which can be devastating if it reaches an Arena Tower. It is also good at simply stalling troops when both the player and the opponent's tower are getting destroyed for the win, granting the edge to the player.
The Freeze's radius is big enough to affect two towers at once. The player can use this to their advantage if they have already gotten one Crown Tower. When their troops come to destroy another, they can cast the Freeze in between the two towers, disabling both of them!
Pairing this card with the Graveyard card could easily make short work of a Crown Tower as the Freeze will prevent the tower and enemy units from killing the skeletons, allowing them to build up.
The Freeze can be deadly, but this card comes with a high risk. Due to the one second delay before a card is placed, it is easy to mistime and cast it after the enemy troops are already defeated, resulting in a waste of four Elixir. This will make the player vulnerable to an enemy's counterattack. It is also a waste of Elixir if the Freeze spell is placed after your attacking troops have already been defeated.
Defensively, Freeze + Valkyrie is a very deadly combo. With the Valkyrie's moderately high splash damage, the player can Freeze the support troops behind a tank (Musketeer, Wizard, Ice Wizard, Archers, etc.) then use the Valkyrie to wipe them out.
Freeze was released with Clash Royale's soft launch on 4/1/16.
On 2/2/16, the February 2016 Update decreased the Freeze's radius to 3 (from 4) and the duration would increase 0.3 seconds per level (from 0.4 seconds).
On 18/5/16, a Balance Update decreased the Freeze's duration by 1 second.
When the Freeze spell has been cast, a pale circle marking its radius will appear, with some snow on the border. The circle line outside the radius will be blue/red, depending on which side the player is on.