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 | 87K | 17.5K | 34w 3d 00h 00m 00s | Troop Health in Towns IV 1, Oracle 36 | 1% | 15K | 37.5K |
| 2 | 135K | 26K | 51w 1d 00h 00m 00s | Troop Health in Towns IV 2, Oracle 36 | 4% | 33K | 47.5K |
| 3 | 180K | 38.5K | 75w 6d 00h 00m 00s> 1 Year(s) | Troop Health in Towns IV 3, Oracle 37 | 8% | 74.5K | 60K |
| 4 | 225K | 57K | 112w 4d 00h 00m 00s> 2 Year(s) | Troop Health in Towns IV 4, Oracle 37 | 12% | 170K | 76K |
| 5 | 270K | 84.5K | 167w 1d 00h 00m 00s> 3 Year(s) | Troop Health in Towns IV 5, Oracle 38 | 17% | 380K | 95.5K |
| 6 | 320K | 130K | 248w 1d 00h 00m 00s> 4 Year(s) | Troop Health in Towns IV 6, Oracle 38 | 23% | 860K | 120K |
| 7 | 375K | 190K | 368w 3d 00h 00m 00s> 7 Year(s) | Troop Health in Towns IV 7, Oracle 39 | 32% | 1.95M | 150K |
| 8 | 450K | 280K | 547w 1d 00h 00m 00s> 10 Year(s) | Troop Health in Towns IV 8, Oracle 39 | 42% | 4.4M | 190K |
| 9 | 595K | 410K | 812w 3d 00h 00m 00s> 15 Year(s) | Troop Health in Towns IV 9, Oracle 40 | 55% | 9.9M | 230K |
| 10 | 910K | 610K | 1 206w 3d 00h 00m 00s> 23 Year(s) | Troop Health in Towns IV 10, Oracle 40 | 70% | 22.5M | 285K |
| 3.55M | 1.84M | 3 623w 5d 00h 00m 00s> 69 Year(s) | 70% | 40.28M | 1.29M |
English