Antewise

Knockout Blow — Regent Attack Card in Slay the Spire 2

Updated 17 Oct 2026 Source Slay the Spire 2 card data (spire-codex.com API), 577 cards retrieved 17 October 2026 By
Data status: The facts on this page were checked against the source named above. Game values can still shift with a patch, so re-check anything that looks off.
Knockout Blow card art
Knockout Blow

Deal 30 damage. If this kills an enemy, gain 5 Stars.

CharacterRegent
TypeAttack
RarityUncommon
Cost3 Energy
TargetAnyEnemy
Total damage30
Per Energy10.00 → 12.67 upgraded

Card text

Deal 30 damage. If this kills an enemy, gain 5 Stars.

Upgraded: Deal 38 damage. If this kills an enemy, gain 5 Stars.

Where it sits on the curve

Measured the same way as our efficiency tier list: total damage divided by Energy.

Knockout Blow produces 10.00 per Energy at base and <strong>12.67</strong> upgraded. That ranks it 24 of 143 of the 143 attacks with a fixed cost. It sits in the top 84% on this measure.

The measure ignores everything that is not a number. Area damage, conditions and drawbacks are not priced in.

Other Regent cards at 3 Energy

  • Bombardment — Deal 18 damage. At the start of your turn, if this is in your Exhaust Pile, play it.
  • Void Form — End your turn. The first 2 cards you play each turn are free to play.

Where to go next

All 577 cards — the full table, filterable by character. Efficiency tier list — every measurable card ranked.

Rarity system explains how often this card appears. Enchantments covers the modifiers that can change it.

Frequently asked questions

What does Knockout Blow do in Slay the Spire 2?

Deal 30 damage. If this kills an enemy, gain 5 Stars.

What does upgrading Knockout Blow change?

Deal 38 damage. If this kills an enemy, gain 5 Stars.

How much does Knockout Blow cost?

3 Energy. It is a Uncommon Attack card.

Is Knockout Blow efficient for its cost?

It produces 10.00 damage per Energy, which ranks 24 of 143 among the attacks that can be measured this way.

More Slay the Spire 2 guides

Sources

Figures and item data on this site are read from the game’s own reference wiki before publishing. Where a value could not be confirmed there, the page says so instead of filling the gap.