Health Regen is the amount of tower health you recover every second. It works alongside your Max Health: the bigger your pool and the faster you refill it, the longer you survive chip damage between kills.
Because so many separate systems multiply it, Health Regen scales from a minor early-game stat into one of the strongest defensive tools in the game once your workshop, lab and card multipliers are all online.
Description
Health Regen is the amount of tower health regenerated per second. It only matters while your tower is below full health, so it pairs naturally with a large Max Health pool — regen refills what enemies manage to take off.
Workshop
Health Regen is unlocked in the workshop for free once you have Health. The workshop line has 6000 upgrades, giving it a very long upgrade path compared to most stats.
Cost
Workshop levels are bought with coins, and the price rises with each upgrade. The cost table below lists the price per level across the full 6000-level track.
| Level | Value | Cost | Total Cost |
|---|---|---|---|
| 1 | 0 | 30 | 0 |
| 100 | 269 | 77.22K | 2.40M |
| 200 | 1.41K | 610.35K | 31.28M |
| 300 | 3.87K | 1.50M | 133.83M |
| 400 | 9.02K | 2.86M | 348.62M |
| 500 | 17.68K | 4.70M | 723.02M |
| 600 | 40.56K | 7.05M | 1.31B |
| 700 | 120.37K | 9.94M | 2.15B |
| 800 | 300.09K | 13.39M | 3.32B |
| 900 | 619.26K | 17.41M | 4.86B |
Cards
Equipping the Health Regen card multiplies your workshop Health Regen value, and this card multiplier stacks multiplicatively with the lab bonus. There are three card-based ways to multiply Health Regen:
- Health Regen Card (common): x2.6 - Health Regen Card (mastery): x5 - Second Wind (mastery): x10 for 400 waves
Workshop Enhancement — Health Regen
The Health Regen workshop enhancement unlocks after you have spent 50 billion coins on defense enhancements. Unlocking it applies a x1 multiplier to Health Regen, and each level adds 0.01x on top. It caps at level 400, which brings the total bonus to x5. Level costs are shown in the table below.
| Level | Value | Coins | Total Coins |
|---|---|---|---|
| 1 | 1.01x | 5.00B | 5.00B |
| 10 | 1.10x | 6.53B | 55.54B |
| 20 | 1.20x | 48.30B | 217.10B |
| 30 | 1.30x | 313.07B | 1.95T |
| 40 | 1.40x | 2.54T | 14.48T |
| 50 | 1.50x | 9.59T | 73.23T |
| 60 | 1.60x | 60.08T | 385.56T |
| 70 | 1.70x | 216.08T | 1.72q |
| 80 | 1.80x | 580.27T | 5.66q |
| 90 | 1.90x | 1.31q | 15.10q |
Lab — Health Regen
The Health Regen lab is available from the start. Researching it increases the increment each workshop level provides and also raises the maximum workshop value, so it makes every future workshop purchase stronger rather than just adding a flat bonus. The lab has 100 levels; the per-level values are listed in the table below.
| Level | Time | Cost | Value |
|---|---|---|---|
| 1 | 0d 0h 0m | 30 | 1.03 |
| 2 | 0d 0h 6m | 71 | 1.06 |
| 3 | 0d 0h 16m | 178 | 1.09 |
| 4 | 0d 0h 31m | 398 | 1.12 |
| 5 | 0d 0h 52m | 772 | 1.15 |
| 6 | 0d 1h 20m | 1,340 | 1.18 |
| 7 | 0d 1h 56m | 2,120 | 1.21 |
| 8 | 0d 2h 39m | 3,170 | 1.24 |
| 9 | 0d 3h 31m | 4,510 | 1.27 |
| 10 | 0d 4h 32m | 6,170 | 1.30 |
Perks
With the labs for +25% standard perks, +10% trade-off perks and unlock-all-perks in a round already researched, perks can supply the following Health Regen bonuses:
- Health Regen x8.8, at the cost of Max Health -60% - Health Regen x5.94
The trade-off option gives the larger multiplier but shrinks your health pool, so weigh it against how much Max Health you rely on.
Relics
Certain relics grant an additional bonus to your Health Regen bonuses, stacking with everything above. The relic table below shows which relics apply and the bonus each one gives.
| # | Rarity | Relic | Value | Source | Event / Type |
|---|---|---|---|---|---|
| 55 | Rare | Coral Crown | 2% | Event | Deep Blue Sea II (Standard) |
| 65 | Rare | Fancy Wires | 2% | Guild | Season 2 |
| 71 | Epic | Retro Camera | 5% | Event | Retrowave II (Standard) |
| 80 | Epic | Cosmic Freedom | 5% | Event | Cthulhu (Standard) |
| 95 | Epic | Star Planet | 5% | Guild | Season 6 |
| 98 | Rare | To Infinity | 2% | Event | Retro Arcade III (Premium) |
| 111 | Rare | Sudden Attack | 2% | Event | Aliens III (Standard) |
| 118 | Epic | Natural Fire | 5% | Event | Into the Storm II (Standard) |
| 120 | Rare | Broken Security | 2% | Event | Glitch (Standard) |
| 278 | Epic | Asteroid Belt | 5% | Event | Meteor Shower (Premium) |