The Auto-Heal upgrade provides periodic healing of 1 HP every few seconds. At low levels, Auto-Heal can be useful to help ease off pressure on your healers. When maxed out, Auto-Heal can heal 10 HP per second and can rival the Vira Savior in healing power. For defensive units such as the Defensive Wall this is an essential upgrade, especially on the Hard and Insane difficulties.
| Level | Upgrade Cost | Delay between heal (secs) |
|---|---|---|
| 1 | 1950 | 2.8 |
| 2 | 2950 | 2.5 |
| 3 | 5450 | 2.2 |
| 4 | 8400 | 1.9 |
| 5 | 11750 | 1.6 |
| 6 | 15450 | 1.3 |
| 7 | 19450 | 1.0 |
| 8 | 23750 | 0.7 |
| 9 | 28350 | 0.4 |
| 10 | 33200 | 0.1 |