“Enhances Iron Output at Ironworks”
| Level | Requirements | Bread | Wood | Stone | Iron | Gold | Upgrade Time | Power | Bonus |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Academy Lv. 15, Bread Output III Lv. 1, Stone Output II Lv. 1, Wood Output III Lv. 1 | 130,000 | 130,000 | 27,000 | 6,700 | 1,600 | 00:25:00 | 1,430 | +5.50% Iron Output |
| 2 | Academy Lv. 16, Iron Output II Lv. 1 | 180,000 | 180,000 | 37,000 | 9,400 | 2,200 | 00:37:30 | 1,430 | +5.50% Iron Output |
| 3 | Academy Lv. 17, Iron Output II Lv. 2 | 400,000 | 400,000 | 81,000 | 20,000 | 4,800 | 01:40:00 | 1,820 | +7.00% Iron Output |