This guide is on hidden teslas. I find in my personal experience of the game that they are the most undervalued and underrated defence in the game.
First of all I would like to start by saying that not enough people upgrade them high enough.
Because of their long build times, hidden teslas are usually built to level one and then not touched again.
However, at max level they have the highest D.P.S in the game (excluding the Inferno Tower which is irrelevant to most players) and only take up a 2 x 2 spacing which can ruin any attack when placed in the right places. They also shoot at a very high rate of fire, one shot per 0.6 seconds, so they are effective for taking out tier 1 troops as well. As the icing on the cake they do DOUBLE DAMAGE TO PEKKAS. Pekkas are one of the strongest troops in the game and a high level will take down a pekka in no time. So please, people, upgrade your Teslas. You will thank me for it when your lvl 6's and 7's start completely ruining your attacker's army.
Teslas have many uses in this game, for all types of base forms. First, if you are a farmer, many people place their teslas next to the otherwise exposed TH. This is a pointless and utterly useless waste of a useful defence as 10 barbs will easily take out an unprotected tesla and the whole point of placing your TH outside your walls is to get a free shield, so please don't do that. A better use for them is to place them in the walls but still covering the TH, which would be placed right up against your walls. This means that while the attacker is focusing on the TH, the teslas can weaken the attack and help you defend your resources. I am a farmer and I use my teslas mostly for killing wall breakers. As a lvl 6 tesla 1 shots a lvl 5 wall breaker, and as teslas shoot at one shot per 0.6 seconds, a high level tesla can take out 3 or 4 wall breakers that otherwise would have breached a hole into your walls.
For the trophy hunters, often there are many 2x2 holes in your base that could hold a hidden tesla.
Looking at the top players in the world, the inside of their base often has many 2x2 holes, which means that the attacker doesn't know where the teslas are, which means you can use them as ninjas, hiding until the last moment then springing up and finishing off those pekkas.
Another use is intimidation. As they are hidden from sight when the player first looks at your base, you might not think that they are very useful for intimidation. However, having one upgrading means the attacker subconsciously assumes that they are all that high level. As a lot of players have low level ones they will be intimidated.
So people, remember to upgrade your teslas. Yes, they are a pain to upgrade and there is nothing worse then waiting 10 or more days for an upgrade, but it is worth it in the end.
Thank you for reading my guide.