"The Mortar is an artillery piece that is effective at medium to long range, but can't target enemies right next to it. Mortar shells explode and deal damage to all troops in the area of effect."
The Mortar is the second defense, and the first splash damage defense, unlocked in the game.
The Mortar has medium DPS and a long reload time.
The Mortar is very effective against massed infantry, so be careful of them when using Riflemen or Zookas. A few Artillery shells from the Gunboat will make short work of it, allowing Riflemen and Zookas to have an easier time destroying the base.
Mortars are very weak against Warriors, as the Warriors are melee troops and attack from inside its range, and move fast enough that they can easily avoid Mortar shots. Warriors can also outheal the damage dealt by even two or three Mortars of equal level.
The Mortar is an extremely effective defense in the removal of large groups of low-health troops such as Riflemen or Zookas. Placing the mortars centrally in your base and protected by other defenses can help your defenses succeed.
It is usually a good idea to put Mortars near the back of your base so Warriors have a hard time reaching them.
It may also be a good idea to put your Mortars near the front of your base. When Troops move up, the Mortar shot is likely to hit Zookas in the back which can ruin an attack.
Initially, the Mortar is a tube-like structure fitted on hinges on a round beige rotatable plate, which is placed on top of two wooden planks.
At level 2, the Mortar's barrel gains a yellow ring.
At level 3, the Mortar gains a gray hexagonal base.
At level 4, the Mortar's hexagonal base turns yellow.
At level 5, the tube becomes longer and larger. The hinge now has a cogwheel under the tube. A metal bar is added in the back.
At level 6, the Mortar's base gains a dark gray plating.
At level 7, the plating added in level 6 is reinforced at each corner.
At level 8, the hinge gets more reinforcement and another, larger cogwheel. The barrel gains reinforcement around its perimeter.
At level 9, the barrel is now colored golden yellow and is slightly larger in size.
At level 11, the barrel becomes much thicker and is now bronze/orange colored, and a worm gear is fitted between the cogwheels. The back of the Mortar also appears to have two bronze colored rods. The base is now thicker as well.
At level 12, the top of the barrel gains a third steel rod added between the two existing rods added in the previous level.
At level 13, the Mortar gains reinforcement in the form of two rods on either side of it next to its hinges.
At level 14, the Mortar's base gains a striped pattern on either side of it.
At level 16, the base is replaced by a hole ringed with copper, and surrounded with iron armor. Protruding from this hole, on a ball-and-socket hinge is a large copper barrel with screws on the front holding the barrel to the hinge, and a large rod on the back. Also the mortar's color shade darkens.
At level 21, the Mortar becomes a very large domed structure with the barrel in the center. The color scheme becomes black, grey, silver, and reddish orange. Large plates, each with five holes in them are bolted on the sides of the structure, and 4 large bolts hold the whole structure to its base. When the Mortar fires, the barrel visibly retracts momentarily.
At level 22, the Mortar gains four piston-like structures in the gaps between the metal plates. When the Mortar fires, these structures extend momentarily.