Iteration Power

Is Iteration good in Slay the Spire 2?

In Slay the Spire 2, Iteration is an uncommon power from the Defect card pool. Its effect: The first time you draw a Status each turn, draw 2 cards. The data flags it as a weaker pick, settling at D tier — usually one to pass on unless your deck specifically wants it.

Over 320 tracked runs its win rate sits at 24.8%, 11.0% ahead of the 13.8% all-deck baseline. It sees niche play, included in only 1.5% of eligible runs. When it is actually offered players take it 14.2% of the time, and that looks correct: those runs win 26.5% against 15.9% for runs that passed, a +10.2% pick lift over 245 decided runs. Within Defect runs it’s drafted 6.8% of the time, making it a regular part of that class’s decks. Decks that include it run about 1.2 copies on average.

Its standout pairing so far is Supercritical, which lifts its win rate by +23.1% when the two share a deck. On the relic side, Captain's Wheel is its standout companion, worth a +25.1% win-rate swing alongside it. It costs 1 energy, gets upgraded 27.1% of the time, and tends to be picked up near floor 17.

Of the runs that drafted it, 78 ended in victory against 236 deaths and 6 abandons. Its most common run-ender is Aeonglass Boss, finishing 6.6% of the runs it shows up in. See the synergies, class split, and threats below for the full picture of where Iteration fits a Defect deck.

Pick or Skip: Iteration

Players take Iteration in 14.2% of the 1850 offers it appears in; those runs win 26.5% against 15.9% for runs that passed, a pick lift of +10.2% over 245 decided runs.

Taken 262 times out of 1850 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 Iteration

Of the 3 pickup windows recorded for Iteration, Act 3 is the best: 50.0% across 41 runs.

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

Best Cards to Pair with Iteration

Iteration’s strongest card pairings so far are Supercritical (+23.1%), Bulk Up (+22.7%), and Flak Cannon (+21.6%), each shown with the win-rate lift it adds.

Supercritical+23.1%39 runsBulk Up+22.7%52 runsFlak Cannon+21.6%47 runsMad Science+18.5%28 runsDefragment+17.8%38 runsRainbow+17.1%15 runs

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

Iteration Win Rate by Class

Exclusive to the Defect, Iteration posts a 24.5% win rate over 312 tracked runs.

The Defectappears in 6.8% of its runs (312 tracked)

Best Relics for Iteration

The relics that swing Iteration’s win rate the most are Captain's Wheel (+25.1%), Meat on the Bone (+25.1%), and Bag of Marbles (+24.4%), with each lift shown.

Captain's Wheel+25.1%17 runsMeat on the Bone+25.1%15 runsBag of Marbles+24.4%55 runsOddly Smooth Stone+24.3%50 runsLetter Opener+23.4%21 runsBlood Vial+22.6%48 runs

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

Iteration Card Details

A 1-energy uncommon power, Iteration is upgraded 27.1% of the time and tends to enter the deck around floor 17.

The first time you draw a Status each turn, draw 2 cards.

What Ends Runs with Iteration

Runs holding Iteration end most often against Aeonglass Boss (6.6%), Test Subject Boss (5.0%), and Queen Boss (4.7%) — the share of its runs each accounts for is shown.

• Aeonglass Boss6.6% of runs
• Test Subject Boss5.0% of runs
• Queen Boss4.7% of runs
• Kaiser Crab Boss4.4% of runs
• Decimillipede Elite3.4% of runs

See Also

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