Unlike the Mirror, Clone duplicates every troop that enters its area of effect.
The upside to this is that Clone can make fragile but strong copies of multiple troops in a medium radius at once for a low cost.
The downside being that mass unit spawning cards may spread out, moving out of the Clone's relatively small radius, resulting in the card not being fully cloned.
It is a good idea to clone a huge push as the clones do the same damage as the original. This includes death damage as well as any slowing or stun effects the original troop may have.
It is beneficial to clone low hitpoint units to maximize their damage dealing capabilities without sacrificing any hitpoints, as the cloned units will always have low hitpoints. The Skeleton Army can be effective to clone. The cloned Skeletons will get killed by most things anyways. Unlike mirroring, it only costs 3 Elixir.
Clone pairs well with the Mirror, as the Mirror duplicates troops and the Clone then clones them, multiplying their numbers exponentially, yet this is a high-risk move as it can easily backfire if the opponent has the right counters. Keep in mind that mirroring first then cloning is one elixir more expensive and 2 out of 4 troops will have the full hitpoints, while cloning then mirroring is often cheaper but only 1 of the 3 troops will have full hitpoints.
It is a good idea to clone troops attacking the enemy Crown Tower(s) if the Tower had locked onto a high hitpoint unit or a Tank.
Clone can create devastating split pushes by cloning a Three Musketeers so that 2 are on one side and 4 are on the other.
Cloning a Giant Skeleton on a tower is devastating, but costs a heavy 9 Elixir.
It is not recommended to clone a melee troop to fight against a ranged troop if the main troop is about to die. However, you can clone a ranged troop with a little less risk against a melee troop because it can offer damage to the enemy before being killed.
Clones will retain most properties of the original troop.
Dark Princes' and Guards' shields can be cloned, allowing them to survive two hits rather than one. Both shield and body will have one hitpoint each.
Clones of any troops that spawn sub-troops will also spawn cloned sub-troops. For example, a cloned Lava Hound will spawn six cloned Lava Pups when it is destroyed.
Clones of any troops that deal Death Damage will also deal Death Damage. For example, a cloned Giant Skeleton will also deal damage.
Clones of troops that deal charge damage like Prince or Dark Prince will also deal double damage when charged.
A cloned Lumberjack will also drop a Rage. With accurate timing, it is also possible to only clone the Rage by placing the Clone right when the Rage bottle drops.
Cloning a troop that has been frozen or slowed will produce a clone that is not frozen. This allows you to negate a defensive Freeze, as the clone will do damage in place of the original while the original remains frozen, while the Crown Tower would have most likely locked onto the real unit.
Cloning the Lava Hound is a very effective strategy. If the cloned copy dies, the Lava Pups will spring out and whether the Crown Tower was originally targeting the real copy or not, the Tower will instantly transfer its target to the real copy (assuming it was still alive) and the Lava Pups will do heavy damage to the Tower. However, it can be easily countered with Zap or Arrows.
Poison and Tornado are extremely effective counters to any clone, as they hit multiple times in their respective areas of effect, effectively eliminating the threat caused by clones of Lava Hounds or shielded troops such as Guards.
Cloned troops always spawn to the right of the original troop, with the original unit pushed to the left to make way. As the real unit will get pushed left, you can use this to bypass buildings with tanks. For example, if your opponent deploys a Cannon to pull your Balloon, you can clone it, resulting in the Balloon being pushed leftwards. The clone will destroy the Cannon but get destroyed by the other Arena Tower, while the real copy can get some hits off the tower. If you spawn your troop on the middle right side of the arena, you can clone them to make them redirect to the left side of the arena.
Clone was added to the game on 9/12/16.
On 13/3/17, the March 2017 Update stopped the Clone from resetting charge attacks of cloned troops. While it will no longer reset charge attacks of the original troops, the clones spawn without being charged, retaining its behavior prior to this change.
The container of this spell looks like that of a Dark Spell from Clash of Clans, though the Clone Spell is an Elixir spell in Clash of Clans.
Cloning bypasses unit deploy times. For example, if a Golem is cloned during his relatively long deploy time, the cloned Golem will start walking without the deploy time finishing.
Clone cannot duplicate previously produced clones.
Unlike its Clash of Clans counterpart, the Clone only produces one clone of a troop regardless of its size; in Clash of Clans, a single troop may produce multiple clones.
This is because of the differing mechanics of the Clone in both games. The Clone Spell in Clash of Clans bases its mechanics off of housing space of individual troops, with higher level Clone Spells being able to clone more troops.
The Clash of Clans Clone spell can only spawn troops that have a limited lifespan while the Clash Royale version spawns permanent but very low health clones.
The upgrades work like that of a Mirror. When leveling up the Clone, the cloned cards' level will be increased. Unlike the Mirror, max-leveled Clone will not clone at max +1 level.