Impervious•Skill

Is Impervious good in Slay the Spire 2?

In Slay the Spire 2, Impervious is a rare skill from the Ironclad card pool. Its effect: Gain 30 Block. Performance-wise it’s a solid if unspectacular include, rated C tier overall.

Over 204 tracked runs its win rate sits at 30.9%, 16.9% ahead of the 14.0% all-deck baseline. It sees niche play, included in only 1.8% of eligible runs. When it is actually offered players take it 33.1% of the time, and that looks correct: those runs win 33.5% against 27.6% for runs that passed, a +5.6% pick lift over 161 decided runs. Within Ironclad runs it’s drafted 7.3% 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 Burning Pact, which lifts its win rate by +19.4% when the two share a deck. On the relic side, Parrying Shield is its standout companion, worth a +22.3% win-rate swing alongside it. It costs 2 energy, gets upgraded 20.9% of the time, and tends to be picked up near floor 20.

Upgrading the card adds +10 Block to its stat line. Of the runs that drafted it, 62 ended in victory against 139 deaths and 3 abandons. Its most common run-ender is Queen Boss, finishing 7.8% of the runs it shows up in. See the synergies, class split, and threats below for the full picture of where Impervious fits a Ironclad deck.

Pick or Skip: Impervious

Players take Impervious in 33.1% of the 520 offers it appears in; those runs win 33.5% against 27.6% for runs that passed, a pick lift of +5.6% over 161 decided runs.

Taken 172 times out of 520 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 Impervious

Of the 4 pickup windows recorded for Impervious, Act 3 is the best: 61.1% across 18 runs.

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

Best Cards to Pair with Impervious

Impervious’s strongest card pairings so far are Burning Pact (+19.4%), Cruelty (+17.7%), and Cascade (+16.1%), each shown with the win-rate lift it adds.

Burning Pact+19.4%31 runsCruelty+17.7%19 runsCascade+16.1%21 runsUnmovable+15.5%29 runsOffering+14.9%24 runsBrand+14.4%30 runs

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

Impervious Win Rate by Class

Exclusive to the Ironclad, Impervious posts a 30.3% win rate over 198 tracked runs.

The Ironcladappears in 7.3% of its runs (198 tracked)

Best Relics for Impervious

The relics that swing Impervious’s win rate the most are Parrying Shield (+22.3%), Centennial Puzzle (+22.1%), and Bag of Preparation (+21.3%), with each lift shown.

Parrying Shield+22.3%24 runsCentennial Puzzle+22.1%44 runsBag of Preparation+21.3%41 runsNunchaku+19.4%28 runsAnchor+18.4%45 runsTuning Fork+17.8%21 runs

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

Impervious Card Details

A 2-energy rare skill, Impervious is upgraded 20.9% of the time and tends to enter the deck around floor 20.

Gain 30 Block.

Upgrade: +10 Block

What Ends Runs with Impervious

Runs holding Impervious end most often against Queen Boss (7.8%), Test Subject Boss (7.8%), and Kaiser Crab Boss (5.9%) — the share of its runs each accounts for is shown.

• Queen Boss7.8% of runs
• Test Subject Boss7.8% of runs
• Kaiser Crab Boss5.9% of runs
• Knowledge Demon Boss5.4% of runs
• Doormaker Boss3.9% of runs

See Also

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