The Lightning card is unlocked from the P.E.K.K.A.'s Playhouse (Arena 4). It is a spell with a wide radius and very high damage. When cast, the Lightning will cause three bolts of lightning to rain down from the sky, targeting the three troops or buildings with the highest hitpoints within its area of effect, dealing very high damage and a brief stun to each. A Lightning card costs 6 Elixir to cast.
- The Lightning spell can be used to finish off Crown Towers with low health or to one shot all troops with less than or as much health as an Electro Dragon.
- The Lightning spell's "health seeking" mechanic makes it very useful for eliminating support troops behind a tank, as it's very likely for two or three units of moderate health to be completely defeated.
- This spell is extremely effective against the Wizard and Witch, especially next to enemy Crown Towers, as it will deal a sizable amount of chip damage for only one extra Elixir while also still being able to strike one more unit.
- This can be done against cheaper units like the Musketeer or Night Witch, but the Elixir deficit may or may not be worth the risk depending on the situation of the match.
- As the Lightning strikes once on each target, it will strike fewer than three times if there are only one or two enemy troops/buildings within its radius, reducing its value.
- When using the Lightning, it is important to designate the targets of the spell in its radius. It is best to refrain from showing the opponent the Lightning until the opportunity for the highest Elixir advantage possible arises.
- When trying to destroy the enemy Crown Tower at the last few seconds of the game, be careful, as any medium-high hitpoint units in its radius will be targeted instead by the Lightning, as in such situations the Crown Tower will have relatively low health, possibly even lower than a Skeleton. Instead, cast the Lightning towards the corner of the tower while it is within its radius to avoid targeting other units surrounding the tower.
- It can be effectively used to counter Three Musketeers to create a 3 Elixir advantage. Avoid hitting the Tower to hit all three of them.
- The Elixir trade-off for using a Lightning can be very high, giving the enemy an Elixir advantage in most cases. However, the Lightning Spell is ineffective against units with extremely high hitpoints such as the Giant or P.E.K.K.A.
- An alternative to the Lightning is the Rocket. Although it utilizes the same amount of Elixir, the Rocket does not discriminate between troops with higher and lower hitpoints and instead damages all troops/buildings in its radius. Keep in mind however, the radius of Rocket is significantly smaller, and have a much longer travel time.
- The Lightning is very effective against the Sparky as it will reset Sparky's damage while also dealing high damage to her and other supporting troops. However, a Lightning will not take out a Sparky of the same level, meaning she is still dangerous if she is still being protected by a tank.
- Royal Hogs can shield Three Musketeers from Lightning since each of them have higher health than a Musketeer.
- The Lightning is very effective against the Inferno Tower and the Inferno Dragon since it can not only heavily damage these units, but also reset their target lock on troops, thus making them take longer to defeat them.
- While the Lightning may stun and cripple an Inferno Tower, it is a negative trade since the Inferno Tower can still damage pushes. Try to damage Crown Towers or other troops to maximize the Lightning's ability to prioritize high hit point units.
- Lightning can also reset charging troops with its stun, so can be used in a pinch to reset charges of the Prince, Dark Prince, and Battle Ram.
- The Lightning card was added with Clash Royale's soft launch on 4/1/16.
- On 19/2/16, the Balance Update decreased the Lightning's Crown Tower damage by 20%.
- On 19/9/16, a Balance Update gave the Lightning the ability to stun targets for 0.5 sec.
- On 9/10/17, the October 2017 Update reduced Lightning's damage by 3%, and its radius to 3 tiles (from 3.5 tiles).
- On 12/12/17, a Balance Update decreased the Lightning’s Crown Tower damage from 40% to 35% of the full damage.
- On 25/4/18, the Clan Wars Update increased the Lightning’s radius to 3.5 (from 3).
- The 20/6/18 Update moved the Arena to unlock the Lightning from Goblin Stadium (Arena 1) to P.E.K.K.A's Playhouse (Arena 4).
- On 3/9/18, a Balance Update increased the Lightning's damage by 5%.
- On 4/8/20, a Balance Update decreased the Lightning's Crown Tower damage from 35% to 30% of the full damage.
- It is tied with the Rocket for the most expensive spell at 6 Elixir, not counting the Mirror which does not have a determined Elixir cost.
- If there are less than three targets in the Lightning's radius, then it will not fire all three bolts. It is possible to waste 6 Elixir this way if there are no units in its radius, as playing the card won't do anything.
- Despite sharing a similar animation, in Clash Royale the Lightning can only hit three buildings or troops whereas in Clash of Clans it can hit any troops or buildings in its damage radius, although it also features lightning bolts.
- The Zap is similar to the Lightning in its appearance and also has an equal-duration stun, but is very different in its attack and use.
- Although the Lightning has a circular radius, it can only hit three targets in that radius, leaving other troops and buildings that were also in the spell radius untouched, a property unique to the Lightning.
- It is one of the five Elixir spells from Clash of Clans to also be in Clash Royale, the others being the Earthquake, Rage, Freeze, and Clone.