A new method of metalworking will make your troops' armor more durable. Conduct the Army Defense II Study and your army will take less damage on the battlefield.
| Level | Food | Lumber | Iron | Stone | Silver | Gold | Time | Requirements | Increased Army Defense | Power | Hero's Experience |
| 1 | 6.25K | 4.25K | 4.25K | 4.25K | 7.5K | 795 | 02h 00m 00s | 1% | 375 | 42K | |
| 2 | 16K | 11K | 11K | 11K | 18.5K | 1.4K | 10h 00m 00s | Academy 19 | 1.15% | 920 | 47.5K |
| 3 | 39.5K | 27K | 27K | 27K | 45.5K | 2.9K | 1d 03h 00m 00s | Academy 19 | 1.35% | 2.3K | 53.5K |
| 4 | 98K | 66.5K | 66.5K | 66.5K | 115K | 5.85K | 2d 15h 00m 00s | Academy 19 | 1.6% | 5.55K | 60K |
| 5 | 245K | 170K | 170K | 170K | 275K | 14K | 1w 00h 00m 00s | Academy 19 | 1.9% | 14K | 67K |
| 6 | 615K | 420K | 420K | 420K | 665K | 31.5K | 2w 3d 00h 00m 00s | Academy 20 | 2.3% | 33.5K | 75.5K |
| 7 | 1.55M | 1.05M | 1.05M | 1.05M | 1.65M | 70.5K | 5w 6d 00h 00m 00s | Academy 20 | 7.3% | 81.5K | 85K |
| 8 | 3.85M | 2.6M | 2.6M | 2.6M | 4M | 165K | 14w 4d 00h 00m 00s | Academy 20 | 14.8% | 200K | 95.5K |
| 9 | 9.55M | 6.5M | 6.5M | 6.5M | 9.75M | 390K | 36w 3d 00h 00m 00s | Academy 20 | 22.8% | 490K | 110K |
| 10 | 24M | 16.5M | 16.5M | 16.5M | 24M | 920K | 90w 6d 00h 00m 00s> 1 Year(s) | Academy 21 | 32.5% | 1.2M | 120K |
| 39.97M | 27.35M | 27.35M | 27.35M | 40.53M | 1.6M | 151w 5d 06h 00m 00s> 2 Year(s) | 32,50% | 2.03M | 756K |
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