It is effective when defending Crown Towers since it will be able to affect both the defensive units and buildings.
A high risk, high reward strategy is to send out a Minion Horde, then use the rage on them. If your opponent's spells and splash units are baited, the Minion Horde can devastate their towers.
Inherently, the Rage is a high-risk, high-reward card that requires good timing in order to succeed. When using Rage, be careful to time it right or else an opposing counter attack will come unhindered due to the player's lack of Elixir.
Place it on as many troops as possible to maximize its effect.
The Rage was added with Clash Royale's soft launch on 4/1/16.
On 29/2/16, the March 2016 Update made the Rage's effect fall off after 2 seconds when troops left the Rage area. Pre-update, the Rage effect would stay with the troop, even if it left the Rage area.
On 23/3/16, a Balance Update increased the Rage's movement and attack speed boost to 40% (from 35%) and decreased its duration by 20%.
On 4/7/16, the Tournament Update changed the Elixir Collector so that the Rage will have an effect on it when the Elixir Collector is in range.
On 19/9/16, a Balance Update decreased the Rage's Elixir cost to 2 (from 3), its attack speed boost to 30% (from 40%) and its duration by 2 sec.
The Rage is very similar to Rage Spell in Clash of Clans, except that the spell increases attack speed instead of damage per hit. It can also speed up the fire-rate of buildings, such as the X-Bow, and boost the spawn speed of spawner buildings and production rate of the Elixir Collector, and can also make the Inferno Tower charge up faster.
The Rage is the cheapest Epic card with a cost of 2 Elixir. (The Mirror can cost the same, but it doesn't have a determined cost).
Unlike its Clash of Clans counterpart, it will not increase the damage per hit of cards.
Along the perimeter of the spell, symbols will light up in sequence like a clock as the spell's duration continues, and the spell fades away when they all light up.
Troops affected by the Rage will sound higher pitched.
It is tied with the Zap and The Log for the cheapest spell in the game.
It is one of only five Elixir spells from Clash of Clans to also be in Clash Royale, the others being the Lightning, Freeze, Heal and Clone.