Boost Away Skill

Is Boost Away good in Slay the Spire 2?

Boost Away is a common Defect skill in Slay the Spire 2. In combat it resolves as: Gain 6 Block. Add a Dazed into your Discard Pile. It currently underperforms most alternatives, sitting at D tier in our Slay the Spire 2 card rankings.

Across 1035 recorded runs, decks running it win 15.6% of the time, comfortably clear of the 13.8% average, by 1.8%. It’s a more selective pick, turning up in just 5.0% of decks that could run it. Offer data is close to a wash — 25.5% of offers taken, 15.6% for runs that picked it against 16.1% for runs that skipped, a pick lift of just -0.4% over 852 decided runs. Defect players keep it in 22.4% 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 +31.5% swing in win rate. It also has strong chemistry with the relic Signet Ring, which moves its win rate by +34.6%. At 0 energy, it’s upgraded in 19.2% of runs and usually joins the deck around floor 12.

Upgraded, it gains +3 Block, which is why so many decks invest a rest-site upgrade in it. That’s 159 wins, 861 deaths, and 15 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Knowledge Demon Boss, which closes out 6.0% of its appearances. Read on for Boost Away’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Defect run.

Pick or Skip: Boost Away

Out of 4351 recorded offers Boost Away is taken 25.5% of the time, and taking it is worth -0.4% in pick lift — 15.6% for runs that picked it against 16.1% for runs that skipped, across 852 decided runs.

Taken 1109 times out of 4351 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 Boost Away

Boost Away is strongest when it joins the deck in Act 3, where runs win 41.5% across 54 runs — one of 4 recorded pickup windows.

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

Best Cards to Pair with Boost Away

Ranked by win-rate lift, Boost Away performs best alongside Mad Science (+31.5%), Production (+28.9%), and Ice Lance (+23.1%).

Mad Science+31.5%57 runsProduction+28.9%16 runsIce Lance+23.1%56 runsBulk Up+22.8%93 runsModded+22.7%88 runsDecay+21.7%21 runs

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

Boost Away Win Rate by Class

Boost Away is drafted only by the Defect, where it holds a 15.6% win rate across 1023 runs.

The Defectappears in 22.4% of its runs (1023 tracked)

Best Relics for Boost Away

Boost Away pairs best with the relics Signet Ring (+34.6%), Toxic Egg (+25.5%), and Data Disk (+25.1%), ranked by win-rate lift.

Signet Ring+34.6%24 runsToxic Egg+25.5%23 runsData Disk+25.1%119 runsTri-Boomerang+24.9%21 runsPunch Dagger+24.3%20 runsRunic Capacitor+23.8%32 runs

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

Boost Away Card Details

Boost Away is a common skill costing 0 energy; it’s upgraded in 19.2% of runs and usually picked up by floor 12.

Gain 6 Block. Add a Dazed into your Discard Pile.

Upgrade: +3 Block

What Ends Runs with Boost Away

Boost Away’s most common run-enders are Knowledge Demon Boss (6.0%), The Insatiable Boss (5.3%), and Aeonglass Boss (4.8%).

• Knowledge Demon Boss6.0% of runs
• The Insatiable Boss5.3% of runs
• Aeonglass Boss4.8% of runs
• Kaiser Crab Boss4.5% of runs
• Infested Prisms Elite4.3% of runs

See Also

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