Deadly Poison•Skill

Is Deadly Poison good in Slay the Spire 2?

Deadly Poison is a common Silent skill in Slay the Spire 2. In combat it resolves as: Apply 5 Poison. It currently underperforms most alternatives, sitting at D tier in our Slay the Spire 2 card rankings.

Across 447 recorded runs, decks running it win 17.5% of the time, comfortably clear of the 14.0% average, by 3.6%. It’s a more selective pick, turning up in just 3.9% of decks that could run it. Taken in 15.6% of its offers, it still trails on the pick-versus-skip split: 17.7% for runs that took it against 25.4% for runs that left it, a -7.5% pick lift over 372 decided runs. Silent players keep it in 15.4% of their runs, so it’s a familiar sight in those decks. On average it shows up 1.4 times in the decks that take it.

It performs best next to Mad Science — together they post a +26.8% swing in win rate. It also has strong chemistry with the relic Razor Tooth, which moves its win rate by +29.7%. At 1 energy, it’s upgraded in 26.7% of runs and usually joins the deck around floor 11.

Upgraded, it gains +2 Poison, which is why so many decks invest a rest-site upgrade in it. That’s 78 wins, 367 deaths, and 2 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Decimillipede Elite, which closes out 5.1% of its appearances. Read on for Deadly Poison’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Silent run.

Pick or Skip: Deadly Poison

Out of 3039 recorded offers Deadly Poison is taken 15.6% of the time, and taking it is worth -7.5% in pick lift — 17.7% for runs that picked it against 25.4% for runs that skipped, across 372 decided runs.

Taken 474 times out of 3039 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 Deadly Poison

Deadly Poison is strongest when it joins the deck in Act 3, where runs win 40.6% across 32 runs — one of 4 recorded pickup windows.

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

Best Cards to Pair with Deadly Poison

Ranked by win-rate lift, Deadly Poison performs best alongside Mad Science (+26.8%), Ultimate Defend (+24.1%), and Burst (+19.5%).

Mad Science+26.8%21 runsUltimate Defend+24.1%23 runsBurst+19.5%46 runsStorm of Steel+19.2%22 runsAdrenaline+18.6%53 runsMalaise+17.9%26 runs

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

Deadly Poison Win Rate by Class

Deadly Poison is drafted only by the Silent, where it holds a 17.6% win rate across 446 runs.

The Silentappears in 15.4% of its runs (446 tracked)

Best Relics for Deadly Poison

Deadly Poison pairs best with the relics Razor Tooth (+29.7%), Snecko Skull (+23.8%), and Miniature Cannon (+23.0%), ranked by win-rate lift.

Razor Tooth+29.7%17 runsSnecko Skull+23.8%45 runsMiniature Cannon+23.0%19 runsBag of Marbles+22.7%54 runsBlood Vial+21.1%54 runsArt of War+21.1%23 runs

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

Deadly Poison Card Details

Deadly Poison is a common skill costing 1 energy; it’s upgraded in 26.7% of runs and usually picked up by floor 11.

Apply 5 Poison.

Upgrade: +2 Poison

What Ends Runs with Deadly Poison

Deadly Poison’s most common run-enders are Decimillipede Elite (5.1%), Kaiser Crab Boss (4.9%), and Knowledge Demon Boss (4.9%).

• Decimillipede Elite5.1% of runs
• Kaiser Crab Boss4.9% of runs
• Knowledge Demon Boss4.9% of runs
• Queen Boss4.3% of runs
• Aeonglass Boss4.3% of runs

See Also

Compare Deadly Poison with the rest of the best Slay the Spire 2 cards, relics, and classes below.