The Arsenal is a building that you upgrade your troops from level 10 to 11, 11 to 12 but you have to have the appropriate building up to level first. Meaning you can not upgrade you cavalry from 10 to 11 unless you can make level 11 in the stables already.
The costs for upgrading troops is less than for making new troops, but remember the upgraded troops will replace the old troops. If you want to keep using the old troops (i personally don't see why, accept for layering) you should not upgrade them. In that case you can make new troops in stables/archer camp etc. You can upgrade more troops in a few days than you can make in the same time.
For instance: i upgraded about 18k cavalry t10 to t11 in 6 days. Making t11 in stables takes about 20 hours for 1.8k. Keep in mind: the time depends on your buffs and research.
Troop upgrade Requirements
In the table below you will find the cost for upgrading 100.000 troops one level.
| Troop | Troop level | Food | Wood | Stone | Ore | Building Upgrades |
|---|---|---|---|---|---|---|
| Ground | 10 | 230.000.000 | 0 | 75.200.000 | 75.200.000 | Barracks lvl 25 |
| Ground | 11 | 350.000.000 | 0 | 120.000.000 | 120.000.000 | Barracks lvl 27 |
| Ground | 12 | 500.000.000 | 0 | 170.000.000 | 170.000.000 | Barracks lvl 30 |
| Ground | 13 | 750.000.000 | 0 | 250.000.000 | 250.000.000 | Barracks lvl 32 |
| Archer | 10 | 75.200.000 | 230.000.000 | 75.200.000 | 0 | Archer camp lvl 25 |
| Archer | 11 | 120.000.000 | 350.000.000 | 120.000.000 | 0 | Archer camp lvl 27 |
| Archer | 12 | 170.000.000 | 500.000.000 | 170.000.000 | 0 | Archer camp lvl 30 |
| Archer | 13 | 250.000.000 | 750.000.000 | 250.000.000 | 0 | Archer camp lvl 32 |
| Cavalry | 10 | 75.200.000 | 75.200.000 | 0 | 230.000.000 | Stables lvl 25 |
| Cavalry | 11 | 120.000.000 | 120.000.000 | 0 | 350.000.000 | Stables lvl 27 |
| Cavalry | 12 | 170.000.000 | 170.000.000 | 0 | 500.000.000 | Stables lvl 30 |
| Cavalry | 13 | 250.000.000 | 250.000.000 | 0 | 750.000.000 | Stables lvl 32 |
| Siege | 10 | 0 | 75.200.000 | 230.000.000 | 75.200.000 | Workshop lvl 25 |
| Siege | 11 | 0 | 120.000.000 | 350.000.000 | 120.000.000 | Workshop lvl 27 |
| Siege | 12 | 0 | 170.000.000 | 500.000.000 | 170.000.000 | Workshop lvl 30 |
| Siege | 13 | 0 | 250.000.000 | 750.000.000 | 250.000.000 | Workshop lvl 32 |
Build Requirements
Build requires Keep 27 first and depending on the troops you want to upgrade an extra building. The arsenal does not upgrade at this time.
Build time depends on your Monarch gear (Strength Crown) and your construction research.
| Keep Level | Food | Wood | Stone | Ore | Building Upgrades |
|---|---|---|---|---|---|
| 27 | 58,000,000 | 74,000,000 | 76,000,000 | 74,000,000 | Keep |