Iron Protection
Increase protected Iron quantity
Max level: 5
Research levels
| Level |  Power |  Food |  Iron |  Coin | Base research time | Requirements |
|---|---|---|---|---|---|---|
| 1 | 3,800 | 1,978,500 | 1,978,500 | 5,935,500 | 2 days 8 hr 9 min |
|
| 2 | 9,200 | 4,154,900 | 4,154,900 | 12,464,600 | 5 days 14 hr 45 min |
|
| 3 | 17,800 | 10,470,300 | 10,470,300 | 31,410,800 | 11 days 7 min |
|
| 4 | 28,800 | 17,014,200 | 17,014,200 | 51,042,600 | 18 days 14 hr 21 min |
|
| 5 | 44,800 | 36,155,200 | 36,155,200 | 108,465,600 | 26 days 18 hr 45 min |
|