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 F tier in our Slay the Spire 2 card rankings.

Across 140 recorded runs, decks running it win 19.7% of the time, right in line with the typical deck. It’s a more selective pick, turning up in just 3.7% of decks that could run it. Silent players keep it in 14.3% 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 Storm of Steel — together they post a +24.6% swing in win rate. It also has strong chemistry with the relic Lizard Tail, which moves its win rate by +22.9%. At 1 energy, it’s upgraded in 26.5% of runs and usually joins the deck around floor 10.

Upgraded, it gains +2 Poison, which is why so many decks invest a rest-site upgrade in it. That’s 24 wins, 98 deaths, and 18 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Knowledge Demon Boss, which closes out 5.7% 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.

Best Cards to Pair with Deadly Poison

Ranked by win-rate lift, Deadly Poison performs best alongside Storm of Steel (+24.6%), Ultimate Defend (+21.3%), and Dagger Throw (+18.5%).

Storm of Steel+24.6%8 runsUltimate Defend+21.3%7 runsDagger Throw+18.5%27 runsTactician+17.7%15 runsBlade of Ink+17.6%6 runsAfterimage+14.8%16 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 19.7% win rate across 140 runs.

The Silentappears in 14.3% of its runs (140 tracked)

Best Relics for Deadly Poison

Deadly Poison pairs best with the relics Lizard Tail (+22.9%), Chandelier (+21.3%), and Bronze Scales (+21.1%), ranked by win-rate lift.

Lizard Tail+22.9%4 runsChandelier+21.3%7 runsBronze Scales+21.1%12 runsHelical Dart+18.5%3 runsSai+18.5%3 runsChoices Paradox+18.5%3 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 26.5% of runs and usually picked up by floor 10.

Apply 5 Poison.

Upgrade: +2 Poison

What Ends Runs with Deadly Poison

Deadly Poison’s most common run-enders are Knowledge Demon Boss (5.7%), Entomancer Elite (5.0%), and Queen Boss (5.0%).

• Knowledge Demon Boss5.7% of runs
• Entomancer Elite5.0% of runs
• Queen Boss5.0% of runs
• Kaiser Crab Boss4.3% of runs
• Ceremonial Beast Boss4.3% of runs

See Also

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