Knockout Blow•Attack

Is Knockout Blow good in Slay the Spire 2?

In Slay the Spire 2, Knockout Blow is an uncommon attack from the Regent card pool. Its effect: Deal 30 damage. If this kills an enemy, gain Stars. The data flags it as a weaker pick, settling at D tier — usually one to pass on unless your deck specifically wants it.

Over 141 tracked runs its win rate sits at 18.6%, 4.6% ahead of the 13.9% all-deck baseline. It sees niche play, included in only 1.2% of eligible runs. Offer data argues the other way: taken 14.2% of the time it is shown, runs that picked it win 19.8% against 32.4% for runs that passed — a -11.5% pick lift across 106 decided runs. Within Regent runs it’s drafted 7.1% of the time, making it a regular part of that class’s decks. Decks that include it run about 1.1 copies on average.

Its standout pairing so far is Dying Star, which lifts its win rate by +20.4% when the two share a deck. On the relic side, Lantern is its standout companion, worth a +30.9% win-rate swing alongside it. It costs 3 energy, gets upgraded 31.6% of the time, and tends to be picked up near floor 12.

Upgrading the card adds +8 Damage to its stat line. Of the runs that drafted it, 26 ended in victory against 114 deaths and 1 abandons. Its most common run-ender is Infested Prisms Elite, finishing 6.4% of the runs it shows up in. See the synergies, class split, and threats below for the full picture of where Knockout Blow fits a Regent deck.

Pick or Skip: Knockout Blow

Players take Knockout Blow in 14.2% of the 810 offers it appears in; those runs win 19.8% against 32.4% for runs that passed, a pick lift of -11.5% over 106 decided runs.

Taken 115 times out of 810 offers.

Pick rate when offered counts offers, not runs: out of every time the game put this in front of a player, how often it was taken. It is not the same number as the share of runs that end up containing it.

Pick lift is the sample-adjusted gap between runs that took the option and runs that passed on it. It is the fair way to rank choices, because raw win rates put the smallest samples on top.

When to Pick Up Knockout Blow

Of the 4 pickup windows recorded for Knockout Blow, Act 2 is the best: 22.2% across 36 runs.

Win rate of runs by the act Knockout Blow entered the deck. Acts that have not reached the sample floor show their run count only.

Best Cards to Pair with Knockout Blow

Knockout Blow’s strongest card pairings so far are Dying Star (+20.4%), Royal Gamble (+16.1%), and Shining Strike (+13.7%), each shown with the win-rate lift it adds.

Dying Star+20.4%23 runsRoyal Gamble+16.1%31 runsShining Strike+13.7%33 runsComet+13.6%30 runsFurnace+13.1%18 runsHegemony+12.2%22 runs

Based on small co-occurring samples — treat these as early signals, not final verdicts.

Knockout Blow Win Rate by Class

Exclusive to the Regent, Knockout Blow posts a 18.6% win rate over 141 tracked runs.

The Regentappears in 7.1% of its runs (141 tracked)

Best Relics for Knockout Blow

The relics that swing Knockout Blow’s win rate the most are Lantern (+30.9%), Festive Popper (+27.0%), and Anchor (+21.6%), with each lift shown.

Lantern+30.9%16 runsFestive Popper+27.0%16 runsAnchor+21.6%17 runsGorget+21.6%17 runsVajra+20.9%15 runsOddly Smooth Stone+18.9%19 runs

Based on small co-occurring samples — treat these as early signals, not final verdicts.

Knockout Blow Card Details

A 3-energy uncommon attack, Knockout Blow is upgraded 31.6% of the time and tends to enter the deck around floor 12.

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

Upgrade: +8 Damage

What Ends Runs with Knockout Blow

Runs holding Knockout Blow end most often against Infested Prisms Elite (6.4%), The Insatiable Boss (5.7%), and Queen Boss (4.3%) — the share of its runs each accounts for is shown.

• Infested Prisms Elite6.4% of runs
• The Insatiable Boss5.7% of runs
• Queen Boss4.3% of runs
• Test Subject Boss4.3% of runs
• Phantasmal Gardeners Elite3.5% of runs

See Also

Keep exploring Slay the Spire 2 tier lists and stats below.