How to upgrade Mortar effectively
By Mortars are one of the first defensive buildings which can be built in game from Town Hall 3, do splash damage but have a quite slow attack speed (5 seconds each shot).
At low Town Hall levels (3-6), Mortars are really important because most players at this level still can’t deploy troops properly and do timing for predicting the next shot of the Mortar. I can see that a lot of lost attack at these Town Hall levels are just because of the Mortars. But are they really important at higher Town Hall levels and how to upgrade them properly?
Although Mortars have pretty slow attack speed and can’t harm troops which stand close less than 4 tiles to them but they can do wipe out a squad of lose HP troops like Barbarians, Archers, Goblins, Wizards and Hog Riders within seconds.
The tables below show you how many hits a mortar need to kill a Barbarian, Archer, Goblin and Wizard at each level.
Mortar Vs. 
Barbarian
| Mortar Level | |||||
| Barbarian Level | 4 | 5 | 6 | 7 | 8 |
| 3 | 2 hits | 2 hits | 2 hits | 2 hits | 1 hit |
| 4 | 3 hits | 2 hits | 2 hits | 2 hits | 2 hits |
| 5 | 3 hits | 3 hits | 3 hits | 2 hits | 2 hits |
| 6 | 4 hits | 3 hits | 3 hits | 2 hits | 2 hits |
Advice: To deal with Barbarians, upgrade your Mortars to at level 4 at TH6 and below, level 5 at TH7 and 8 is enough and level 7 at TH9 and 10.
Mortar Vs. 
Archer
| Mortar Level | |||||
| Archer Level | 4 | 5 | 6 | 7 | 8 |
| 3 | 1 hit | 1 hit | 1 hit | 1 hit | 1 hit |
| 4 | 1 hit | 1 hit | 1 hit | 1 hit | 1 hit |
| 5 | 2 hits | 1 hit | 1 hit | 1 hit | 1 hit |
| 6 | 2 hits | 2 hits | 1 hit | 1 hit | 1 hit |
Advice: To be safe against Archers, you just need level 4 Mortar at TH6 and below, level 5 at TH7, 8 and level 6 at TH9 and 10.
Mortar Vs. 
Goblin
| Mortar Level | |||||
| Goblin Level | 4 | 5 | 6 | 7 | 8 |
| 3 | 2 hits | 1 hit | 1 hit | 1 hit | 1 hit |
| 4 | 2 hits | 2 hits | 1 hit | 1 hit | 1 hit |
| 5 | 2 hits | 2 hits | 2 hits | 1 hit | 1 hit |
| 6 | 3 hits | 2 hits | 2 hits | 2 hits | 1 hit |
Advice: To deal with Goblins, you should upgrade your Mortar to level 7 at TH 9 and 10, level 6 at TH7 and 8 and level 4 at TH6 and below.
Mortar Vs. 
Wizard
| Mortar Level | |||||
| Wizard Level | 4 | 5 | 6 | 7 | 8 |
| 3 | 4 hits | 3 hits | 3 hits | 2 hits | 2 hits |
| 4 | 4 hits | 4 hits | 3 hits | 3 hits | 2 hits |
| 5 | 5 hits | 4 hits | 4 hits | 3 hits | 2 hits |
| 6 | 5 hits | 5 hits | 4 hits | 3 hits | 3 hits |
Advice: To be safe against Wizards, upgrade your Mortars to their maximum level at TH 8 and below and at least level 7 from TH9.
Conclusion
Base on those tables below, I can say Mortars are always one of the most powerful defensive buildings in order to deal with most common attack strategies like Barch or B.A.M at all Town Hall levels, especially at TH 6 and below, where most players still can’t do timing the next shot of the Mortar to drop troops properly. The places where you put the Mortars are very important. Don’t make them be exposed but always ensure that they can cover the whole base. You can refer plenty of nice bases with perfect Mortar placements here.
You should always upgrade your Mortars to their maximum level at TH6 and below, at least level 6 at TH7 and 8 and max them out at TH9 and 10.
Do you have any advice for upgrading Mortars?
