Second Wind

Last verified 2026-07-29 · 2 data tables

Second Wind is a defensive card that gives your tower a second chance. When your tower takes lethal damage, this ability brings it back to life with half its health and surrounds it with an invincible shield for a limited time. It can only trigger once per round, making it a crucial safety net for surviving difficult waves.

Description

When your tower would be destroyed, Second Wind activates to revive it with 50% health. It also creates an invincible shield that lasts for a duration based on the card's level, ranging from 10 to 40 seconds. This effect can only occur once per round.

Use

Second Wind is part of a hierarchy of death prevention abilities that activate in a specific order. If lethal damage is incoming, the game checks for other defenses first. Death Defy gets the first chance to activate. If that fails, Energy Shield will use a charge to block the damage. Only if neither of those is available will Second Wind trigger. After Second Wind, Demon Mode and Nuke can also activate if you have their respective Smart Automation labs researched. Note that Smart Nuke Automation also grants 15 seconds of invulnerability as of version 27.3.

Labs — Second Wind Blast

This lab is unlocked in Milestones at tier 3 wave 150. It adds an offensive effect to Second Wind, causing it to clear a percentage of spawned enemies when it triggers. The lab has 4 levels, with each level increasing the percentage of enemies cleared.

LevelTimeCostValue
11d  3h 46m1,800,00025%
21d 17h 39m3,000,00050%
32d  7h 33m4,500,00075%
43d 11h 19m75,000,000100%

Labs — Recharge Second Wind

Unlocked in Milestones at tier 14 wave 60, this lab allows Second Wind to recharge after it has been used. Instead of being available only once per round, it can activate again after a set number of waves has passed. This lab has 7 levels, reducing the number of waves required to recharge.

LevelTimeCostValue
15d  4h  59m550B2,000
26d  14h  21m1,05T1,500
38d  54m  39s1,55T1,250
49d  23h  10m2,05T1,000
514d  1h  58m2,56T750
624d  19h  29m3,07T550
751d  8h  11m3,6T400

Related pages

Written for Tower Hub. Numbers and mechanics were cross-checked against our decoded save data and the community's Fandom wiki (community page last edited 2026-01-20). Something out of date? Tell us in the Discord.

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