The Tesla is effective against small hordes of troops, such as Skeletons, and can zap away some health from moderate health troops at a decent rate. It also deals moderate damage to higher hitpoint troops such as the Baby Dragon, and can also take out a Lava Hound and its pups without any assistance.
When it retreats underground, the Tesla is unaffected by damage-dealing spells such as the Rocket and Lightning, and cannot be targeted by any troops. However, the retreat is not instant, enabling quick troops like Spear Goblins to get a hit off before it goes underground. The retreat can also be stopped with a Freeze spell, enabling the player to attack the Tesla at leisure.
The Tesla can be frozen by the Freeze while underground, so it won't pop up when enemies are in range while the Freeze is active on it. This allows troops to bypass a Tesla and head straight for the Crown Tower, as it can't be targeted while hidden underground.
Although the Tesla has the same range as a Cannon, it can still target troops that would normally outrange it due to its ability to become invulnerable when not attacking, forcing them to come into its targeting range before they can target it. Thus, when using long-range units, the player should provoke the Tesla with another troop first to prevent the long-range troop(s) from wandering into its range and being destroyed.
The Tesla is great at distracting enemy troops that target buildings, such as the Giant and Hog Rider. By placing it in the middle of the player's part of Arena, the troops will target it instead of the Towers if it is not frozen.
The Tesla's re-targeting is rather slow, meaning that the player should send troops in large groups when attacking an enemy's Tesla (like Skeleton Army).
The Tesla can target both air and ground troops and has a smaller hitbox. It also has more health and damage, so it can be interchangeable with the Cannon. It costs 1 more Elixir which is the major downside, however.
Unlike other buildings, the Tesla takes up a 2x2 space as opposed to a 3x3 space. This means that it can fit in the gap between a Princess Tower and the edge of the Arena.
It can support siege buildings like X-Bows or Mortars from your side of the Arena.
The Tesla was added with Clash Royale's soft launch on 4/1/16.
The Tesla's mechanics are similar to its counterpart in Clash of Clans, the level 1 Hidden Tesla which it resembles. However, in Clash of Clans, the Tesla does not retreat underground when it is not actively attacking; it simply remains above ground for the rest of the attack.
The Tesla is the only defense that can be placed symmetrically.
The Tesla is the smallest building in the game.
It is named after the Tesla coil, a device invented by Nikola Tesla which can produce large amounts of AC current in frightening display. However, despite its name the Tesla does not include the namesake device in Clash Royale.
The Tesla is the only building which retreats underground when it finishes attacking.
The word 'electrickery' is a play on words, and a reference to the Tesla's description in Clash of Clans.
If the Tesla is about to retreat and the Freeze is used on it, the retreating sound effect will loop.
The Tesla is the only Common building so far that can target flying troops.