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 | Gold | Soul Shard | Time | Requirements | Warrior Healing Speed | Influence | Hero’s Experience |
| 1 | 110K | 22K | 6w 1d 00h 00m 00s | Troop Defense When Attacking Towns I 1, Oracle 36 | 1% | 18.5K | 46.5K |
| 2 | 170K | 32.5K | 63w 6d 00h 00m 00s> 1 Year(s) | Troop Defense When Attacking Towns I 2, Oracle 36 | 3% | 41.5K | 59K |
| 3 | 225K | 48K | 94w 5d 00h 00m 00s> 1 Year(s) | Troop Defense When Attacking Towns I 3, Oracle 37 | 5% | 93K | 75K |
| 4 | 280K | 71K | 140w 5d 00h 00m 00s> 2 Year(s) | Troop Defense When Attacking Towns I 4, Oracle 37 | 7% | 210K | 95K |
| 5 | 340K | 110K | 208w 6d 00h 00m 00s> 4 Year(s) | Troop Defense When Attacking Towns I 5, Oracle 37 | 9% | 475K | 120K |
| 6 | 400K | 160K | 310w 1d 00h 00m 00s> 5 Year(s) | Troop Defense When Attacking Towns I 6, Oracle 38 | 12% | 1.1M | 150K |
| 7 | 465K | 235K | 460w 4d 00h 00m 00s> 8 Year(s) | Troop Defense When Attacking Towns I 7, Oracle 38 | 15% | 2.45M | 190K |
| 8 | 565K | 345K | 683w 6d 00h 00m 00s> 13 Year(s) | Troop Defense When Attacking Towns I 8, Oracle 38 | 19% | 5.5M | 235K |
| 9 | 745K | 515K | 1 015w 4d 00h 00m 00s> 19 Year(s) | Troop Defense When Attacking Towns I 9, Oracle 39 | 24% | 12.5M | 290K |
| 10 | 1.15M | 760K | 1 508w 1d 00h 00m 00s> 28 Year(s) | Troop Defense When Attacking Towns I 10, Oracle 39 | 30% | 28M | 355K |
| 4.45M | 2.3M | 4 492w 4d 00h 00m 00s> 86 Year(s) | 30% | 50.39M | 1.62M |
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