By researching the properties of various herbs, your healers will be able to improve the recipe for a potion that helps wounds to heal faster. Upgrading this Knowledge will boost the healing speed of warriors in the Infirmary.
| Level | Food | Lumber | Iron | Stone | Silver | Gold | Time | Requirements | Increased Warrior Healing Speed | Influence | Hero’s Experience |
| 1 | 5K | 3.25K | 3.25K | 0 | 6K | 665 | 01h 30m 00s | 1 | 300 | 21K | |
| 2 | 12.5K | 8.15K | 8.15K | 0 | 15K | 1.15K | 07h 30m 00s | Oracle 13 | 3 | 750 | 25.5K |
| 3 | 31.5K | 20.5K | 20.5K | 0 | 37.5K | 2.35K | 21h 00m 00s | Oracle 14 | 5 | 1.9K | 31K |
| 4 | 78.5K | 51K | 51K | 0 | 94K | 4.55K | 2d 00h 00m 00s | Oracle 15 | 8 | 4.7K | 37.5K |
| 5 | 200K | 130K | 130K | 0 | 235K | 10.5K | 5d 00h 00m 00s | Oracle 16 | 12 | 12K | 45.5K |
| 6 | 490K | 320K | 320K | 0 | 590K | 24K | 1w 6d 00h 00m 00s | Oracle 17 | 17 | 29.5K | 55.5K |
| 7 | 1.25M | 795K | 795K | 0 | 1.5M | 53.5K | 4w 3d 00h 00m 00s | Oracle 18 | 24 | 73.5K | 67K |
| 8 | 3.1M | 2M | 2M | 0 | 3.7M | 125K | 11w 00h 00m 00s | Oracle 19 | 34 | 185K | 81.5K |
| 9 | 7.65M | 5M | 5M | 0 | 9.2M | 295K | 27w 2d 00h 00m 00s | Oracle 20 | 54 | 460K | 99K |
| 10 | 19.5M | 12.5M | 12.5M | 0 | 23M | 690K | 68w 1d 00h 00m 00s> 1 Year(s) | Oracle 21 | 79 | 1.15M | 120K |
| 32.32M | 20.83M | 20.83M | 38.38M | 1.21M | 113w 6d 06h 00m 00s> 2 Year(s) | 79 | 1.92M | 583.5K |
English