Defending a Fortress is a matter of honor for Heroes. In the name of their Jarl, they will do everything they can to thwart enemy attempts to capture the location. Upgrading this Knowledge increases your troops' defense when guarding Fortresses.
| Level | Scrolls | Precious Dust | Gold | Time | Requirements | Troop Defense When Guarding Fortresses | Influence | |
| 1 | 250 | 10 | 41.5K | 1w 12h 00m 00s | Shamans' Residence 4 | 1 | 13M | |
| 2 | 330 | 15 | 53K | 1w 3d 12h 00m 00s | - | 2nd, | >5 | 13M | |
| 3 | 435 | 20 | 71.5K | 2w 1d 12h 00m 00s | - | 5 | 13.5M | |
| 4 | 585 | 25 | 97.5K | 3w 2d 00h 00m 00s | - | 8, | >5 | 13.5M | |
| 5 | 810 | 40 | 145K | 5w 2d 00h 00m 00s | - | 14 | 13.5M | |
| 6 | 1 150 | 70 | 230K | 8w 6d 12h 00m 00s | - | 20 | 13.5M | |
| 7 | 1 650 | 120 | 380K | 15w 5d 12h 00m 00s | - | 30 | 14M | |
| 8 | 2 450 | 220 | 665K | 29w 3d 00h 00m 00s | - | 40 | 14M | |
| 9 | 3 600 | 435 | 1.25M | 57w 4d 12h 00m 00s> 1 Year(s) | - | 50 | 14M | |
| 10 | 5 500 | 890 | 2.4M | 118w 5d 12h 00m 00s> 2 Year(s) | - | 60 | 14.5M | |
| 16.76K | 1.85K | 5.33M | 243w 6d 12h 00m 00s> 4 Year(s) | 60 | 5 | 136.5M |
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