Whistle•Attack

Is Whistle good in Slay the Spire 2?

Whistle is an ancient Event attack in Slay the Spire 2. In combat it resolves as: Deal 33 damage. Stun the enemy. It’s a dependable, middle-of-the-pack option, landing at C tier in our rankings.

Across 12 recorded runs, decks running it win 33.3% of the time, comfortably clear of the 18.9% average, by 14.4%. It’s a more selective pick, turning up in just 0.3% of decks that could run it. Silent players keep it in 0.1% of their runs, so it’s a familiar sight in those decks. On average it shows up 1.0 times in the decks that take it.

It performs best next to Unmovable — together they post a +4.8% swing in win rate. It also has strong chemistry with the relic Vajra, which moves its win rate by +8.9%. At 3 energy, it’s upgraded in 33.3% of runs and usually joins the deck around floor 34.

Upgraded, it gains +11 Damage, which is why so many decks invest a rest-site upgrade in it. That’s 4 wins, 8 deaths, and 0 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Test Subject Boss, which closes out 25.0% of its appearances. Read on for Whistle’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Event run.

Best Cards to Pair with Whistle

Ranked by win-rate lift, Whistle performs best alongside Unmovable (+4.8%), Strike (+2.2%), and Bash (+2.2%).

Unmovable+4.8%4 runsStrike+2.2%5 runsBash+2.2%5 runsDefend+2.2%5 runsInflame+2.2%5 runsDefend0.0%3 runs

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

Whistle Win Rate by Class

Whistle is played across 4 classes, led by Silent (100.0%), Ironclad (40.0%), and Necrobinder (33.3%) by win rate.

The Silent100.0%1 runsThe Ironclad40.0%5 runsThe Necrobinder33.3%3 runsThe Regent0.0%3 runs

Best Relics for Whistle

Whistle pairs best with the relics Vajra (+8.9%), Juzu Bracelet (+7.7%), and Cloak Clasp (+7.7%), ranked by win-rate lift.

Vajra+8.9%5 runsJuzu Bracelet+7.7%3 runsCloak Clasp+7.7%3 runsBronze Scales+7.7%3 runsKusarigama+7.7%3 runsCandelabra+7.7%3 runs

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

Whistle Card Details

Whistle is an ancient attack costing 3 energy; it’s upgraded in 33.3% of runs and usually picked up by floor 34.

Deal 33 damage. Stun the enemy.

Upgrade: +11 Damage

What Ends Runs with Whistle

Whistle’s most common run-enders are Test Subject Boss (25.0%).

• Test Subject Boss25.0% of runs

See Also

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