Prolong•Skill

Is Prolong good in Slay the Spire 2?

In Slay the Spire 2, Prolong is an uncommon skill from the Colorless card pool. Its effect: Next turn, gain Block equal to your current Block. Right now it’s a premium pick that sits at B tier — one of the better cards you can add to a deck this run.

Over 122 tracked runs its win rate sits at 40.5%, 26.4% ahead of the 14.1% all-deck baseline. It sees niche play, included in only 1.2% of eligible runs. When it is actually offered players take it 4.5% of the time, and that looks correct: those runs win 47.8% against 25.9% for runs that passed, a +15.3% pick lift over 23 decided runs. Within Ironclad runs it’s drafted 1.4% 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 Bloodletting, which lifts its win rate by +21.2% when the two share a deck. On the relic side, Anchor is its standout companion, worth a +27.2% win-rate swing alongside it. It costs 0 energy, gets upgraded 45.0% of the time, and tends to be picked up near floor 21.

Of the runs that drafted it, 49 ended in victory against 72 deaths and 1 abandons. Its most common run-ender is Knowledge Demon Boss, finishing 4.9% of the runs it shows up in. See the synergies, class split, and threats below for the full picture of where Prolong fits a Colorless deck.

Pick or Skip: Prolong

Players take Prolong in 4.5% of the 514 offers it appears in; those runs win 47.8% against 25.9% for runs that passed, a pick lift of +15.3% over 23 decided runs.

Taken 23 times out of 514 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 Prolong

Of the 3 pickup windows recorded for Prolong, Act 3 is the best: 72.7% across 33 runs.

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

Best Cards to Pair with Prolong

Prolong’s strongest card pairings so far are Bloodletting (+21.2%), Battle Trance (+18.9%), and Flame Barrier (+15.7%), each shown with the win-rate lift it adds.

Bloodletting+21.2%16 runsBattle Trance+18.9%17 runsFlame Barrier+15.7%15 runsPommel Strike+14.8%19 runsDualcast+9.7%16 runsBody Slam+9.7%20 runs

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

Prolong Win Rate by Class

Of the 5 classes that draft Prolong, it performs best with Ironclad (50.0%), Defect (50.0%), and Necrobinder (40.0%).

The Ironclad50.0%34 runsThe Defect50.0%18 runsThe Necrobinder40.0%21 runsThe Silent31.0%29 runsThe Regent22.2%18 runs

Best Relics for Prolong

The relics that swing Prolong’s win rate the most are Anchor (+27.2%), Oddly Smooth Stone (+24.4%), and Happy Flower (+23.7%), with each lift shown.

Anchor+27.2%27 runsOddly Smooth Stone+24.4%24 runsHappy Flower+23.7%15 runsFestive Popper+23.7%15 runsBronze Scales+23.5%26 runsVajra+20.8%39 runs

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

Prolong Card Details

A 0-energy uncommon skill, Prolong is upgraded 45.0% of the time and tends to enter the deck around floor 21.

Next turn, gain Block equal to your current Block.

What Ends Runs with Prolong

Runs holding Prolong end most often against Knowledge Demon Boss (4.9%), Queen Boss (4.1%), and Kaiser Crab Boss (4.1%) — the share of its runs each accounts for is shown.

• Knowledge Demon Boss4.9% of runs
• Queen Boss4.1% of runs
• Kaiser Crab Boss4.1% of runs
• Decimillipede Elite4.1% of runs
• Aeonglass Boss3.3% of runs

See Also

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