"The Mortar can mow down hordes of enemies by the splash damage from its shell. Don't let enemies get too close to it!"
Mortars are the player's heavy defenses. Whenever an enemy comes into range, it blasts out an explosive shell that deals area damage.
Starting at level 8, the Master Builder in the Builder Base can Gear Up a single Mortar to make it resemble a Multi Mortar. The geared up Mortar will fire its shots in bursts of three.
Your Multi Mortar, however, needs to be level 8.
Mortars shoot long-range explosive shells every 5 seconds which deal devastating splash damage to every ground unit within a small radius of the impact point. Their splash damage, combined with their long range, make them deadly weapons against large groups of weaker enemies such as Barbarians, Archers, or Goblins. Multiple mortars can sweep away giants and wizards.
A Mortar's major disadvantages are its inability to attack troops within its 4-tile blind spot, its low rate of fire and low DPS which makes them less effective against high-health troops. It also cannot attack air troops, such as Balloons.
The Mortar's low Damage per Second is due to its very slow firing speed; multiplying its DPS by 5 (its hit speed) will give you its damage per shot, which is the important stat for Mortars.
Due to the fact that the Mortar's shell takes a while to reach its target (over a second at maximum range), fast troops like Goblins can easily dodge its attack if they are moving when the Mortar fires.
Mortars should generally be placed towards the center of your base, preferably behind at least one set of Walls, because its long range allows the Mortar to attack from far behind other structures.
Since the Mortar deals heavy splash damage, it can quite rapidly eliminate attacking troops.
It is smart to form a triangle or square with your Mortars near the center of your base, as this allows multiple Mortars to attack the same area.
At each level, the Mortar can kill a same-level Archer in a single shot. i.e. A level 1 Mortar can one-shot level 1 Archers, level 2 can one-shot level 2 Archers, etc.
Putting a Mortar and Wizard Tower together makes a smart pair because the Mortar covers a large area while the Wizard Tower helps protect the Mortar from mass air troops and covers the Mortar's blind spot.
However, it is not a very good idea to place the two towers right next to each other (or separated by a single wall), because two or three appropriately leveled Lightning Spells can take them out easily. Try to put another building in between them if possible.
It is a good idea to place Mortars near each other, without putting them in the same wall pocket (if possible). When more than one Mortars' range overlaps, it creates a kill-zone where almost no low-health troops can survive.
Take care when upgrading, as many players use this as a chance to attack. For this reason, it is a good idea to only upgrade one Mortar at a time. However, upgrading all of them at once is also viable, as it gets the upgrades out of the way quickly, leaving you more time to benefit from all Mortars being online and maxed out at your current Town Hall level.
A good strategy placement against all types of attacks is putting your mortar by a Wizard Tower and an Air Defense with a storage. The storage acts as a damage sponge, while the defenses will take out hordes of troops.
At high levels where Mortars may be less relevant, you can place them outside your Walls, in the corners, to prevent Archers from easily sniping other non-defensive buildings. However, without additional protection, these buildings are vulnerable to Wizards or Minions, the former being able to survive a shot or two from the Mortar while the latter is invulnerable to the Mortar.
The Mortar's blind spot, low rate of fire, and inability to target air troops make them vulnerable to a wide variety of different attacks. Fast melee troops such as Barbarians or Goblins (after all resource structures are destroyed) can rush to the Mortar and quickly enter its blind spot. Unfortunately, Archers will always stop and begin firing at a Mortar before they enter its blind spot, so pairing them with a meat shield is ideal.
If a building is protected only by a Mortar, using a Wizard or two can easily destroy it if you are using a ground attack.
Mortars undergo significant visual changes at levels 5, 6, 7, 8, 10 and 11.
When initially constructed, the Mortar consists of a solid black launcher tube with two half-disc gimbals on each side. It fires a gray stone shell.
The level 2 and 3 Mortars grow larger and sport an increasingly wider gold trim on the outer rim of the tube.
At level 4, the Mortar's gimbals change to a bright golden color, and it sports a wider, pitted ring of gold trim. Its shell changes to a black stone.
At level 5, the Mortars gold rim reaches its greatest width.
At level 6, the Mortar's exterior turns entirely golden. Its shell becomes a golden fiery ball.
At level 7, the Mortar's exterior reverts to black with golden trim, but acquires a skull on each gimbal (which turn black as well) and bones and another skull on the ground in front of it.
At level 8, the Mortar's color becomes metallic, and the barrel's internals glows with what appears to be lava. The golden fiery ball becomes noticeably larger. The gimbal of the mortar also becomes bigger in a somewhat trapezoid shape. Spikes appear on the ring around the top of the mortar, replacing the skulls of the former level.
At level 9, the plating becomes white stone, and the barrel gets bigger and more elongated, and gains rifling. The number of spikes on the gimbal is reduced to 3, while the spikes on the rim become one huge spike instead of 5 small ones. There is a gold chain connecting the two halves of the gimbal. The projectile becomes slightly larger, has more bulk to it, and rotates when it flies through the air.
At level 10, the gimbal gains red stone, the rifling in the barrel disappears and the glow from the inside of the barrel becomes much more intense. The white stone plating changes pattern slightly and the gaps between the plating glow red. The barrel greatly increases in size.
At level 11, the gimbals are now metallic with golden links; each gimbal has a metal piece which is bolted to the building. The Mortar's exterior now consists of gray spiked plates, and there is a golden studded band just beneath the barrel of the Mortar.
There is an Achievement called Mortar Mauler that rewards the player for destroying a certain number of Mortars in raids.
Every time a Mortar shell impacts the ground, the screen shakes slightly.
The Mortar shell's explosion is so powerful that it knocks back smaller Troops. It is possible that a troop, after getting knocked back, will change their targets depending on the current situation.
The Mortar is one of the three Defensive Buildings (along with the Cannon and X-Bow) that rotate themselves to aim at different targets, as the Air Defense is made of rockets, while the others are towers. These three face away from the Town Hall when the village is not under attack.
Up until level 6, the even number level Mortars have 3 studs on the rim, and the odd number level Mortars have 1 stud on the rim, except level 1.
As of the October 2016 update, Town Hall 11 is the only Town Hall level that has 2 available Mortar upgrades.
Tapping this icon displays information about the Mortar, such as Level, Damage Per Second, Hitpoints, Range, Damage Type and Targets.
Tapping this icon begins upgrading the Mortar to the next level, if you have enough resources and a free Builder. When the Mortar is at maximum level, this icon is not shown.
Tapping this icon instantly upgrades the Mortar to the next level, at the cost of one Hammer of Building if you have one. When the Mortar is at maximum level, this icon is not shown.
Tapping this icon, which is displayed only while an upgrade is in progress, instantly finishes that upgrade at the cost of the displayed number of Gems.
Tapping this icon, which is displayed only while an upgrade is in progress, instantly finishes that upgrade at the cost of one Book of Building. This icon is only shown if you have at least one Book of Building.
Tapping this icon, which is displayed only while an upgrade is in progress, boosts all your Builders for 1 hour by a factor of ten, at the cost of one Builder Potion. This icon is only shown if you have at least one Builder Potion.
Tapping this icon, which is displayed only while an upgrade is in progress, cancels the current upgrade and refunds half of the upgrade cost.
Tapping this icon gears up the Mortar, if you have upgraded it enough to do so, have enough resources and a free Master Builder. If any Mortar is already geared up, this icon will not appear.
This icon informs you that the Mortar cannot be geared up because it is insufficiently upgraded. Tapping this icon will tell you the required level to gear up this Mortar. If any Mortar is already geared up, this icon will not appear.
Tapping this icon switches the Mortar to Burst mode. This icon only appears when the Mortar is geared up, and is in Normal mode.
Tapping this icon switches the Mortar to Normal mode. This icon only appears when the Mortar is geared up, and is in Burst mode.