Subroutine•Power

Is Subroutine good in Slay the Spire 2?

Subroutine is an uncommon Defect power in Slay the Spire 2. In combat it resolves as: Whenever you play a Power, gain -cost. It’s a dependable, middle-of-the-pack option, landing at C tier in our rankings.

Across 103 recorded runs, decks running it win 29.6% of the time, comfortably clear of the 19.0% average, by 10.6%. It’s a more selective pick, turning up in just 2.7% of decks that could run it. Defect players keep it in 17.5% 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 Hologram — together they post a +20.3% swing in win rate. It also has strong chemistry with the relic Red Mask, which moves its win rate by +24.1%. At 1 energy, it’s upgraded in 40.1% of runs and usually joins the deck around floor 16.

Upgraded, it gains -1 EnergyCost, which is why so many decks invest a rest-site upgrade in it. That’s 26 wins, 62 deaths, and 15 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Kaiser Crab Boss, which closes out 4.9% of its appearances. Read on for Subroutine’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Defect run.

Best Cards to Pair with Subroutine

Ranked by win-rate lift, Subroutine performs best alongside Hologram (+20.3%), Machine Learning (+20.3%), and Scrape (+20.3%).

Hologram+20.3%26 runsMachine Learning+20.3%19 runsScrape+20.3%17 runsSkim+18.1%15 runsFusion+17.6%10 runsEnergy Surge+16.3%3 runs

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

Subroutine Win Rate by Class

Subroutine is played across 2 classes, led by Defect (29.9%) and Regent (0.0%) by win rate.

The Defect29.9%102 runsThe Regent0.0%1 runs

Best Relics for Subroutine

Subroutine pairs best with the relics Red Mask (+24.1%), Joss Paper (+23.5%), and Data Disk (+22.6%), ranked by win-rate lift.

Red Mask+24.1%16 runsJoss Paper+23.5%5 runsData Disk+22.6%11 runsPendulum+22.4%13 runsBlood Vial+20.3%18 runsLasting Candy+20.3%12 runs

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

Subroutine Card Details

Subroutine is an uncommon power costing 1 energy; it’s upgraded in 40.1% of runs and usually picked up by floor 16.

Whenever you play a Power, gain -cost.

Upgrade: -1 EnergyCost

What Ends Runs with Subroutine

Subroutine’s most common run-enders are Kaiser Crab Boss (4.9%), Knowledge Demon Boss (3.9%), and Queen Boss (3.9%).

• Kaiser Crab Boss4.9% of runs
• Knowledge Demon Boss3.9% of runs
• Queen Boss3.9% of runs
• Knights Elite3.9% of runs
• The Insatiable Boss2.9% of runs

See Also

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