Should I upgrade Subroutine in Slay the Spire 2?

Compare the upgraded text: Cost changes from 1 to 0. If the upgrade lowers cost, adds damage/block, or enables a combo piece, it is usually high priority.

What builds use Subroutine?

Subroutine appears in 2 tracked builds: Storm Conductor (S-tier, flex pick), Machine Mind (B-tier, core card).

What character uses Subroutine?

Subroutine is tagged as a Defect card. See the Defect build hub for archetypes that care about it.

Updated for Data 2026-03-17Early Access — numbers may shift with patches.

Subroutine

Defect · Power · Uncommon · 1 cost

Base

Upgraded

Card text

Whenever you play a Power, gain 1 Energy.

Subroutine+

Cost changes from 1 to 0

Builds that use Subroutine

Archetypes that draft this card in real runs, with the role it plays.

Build context

See the Defect build hub for archetypes that feature this card in real runs.

Related cards

Subroutine FAQ

Should I upgrade Subroutine in Slay the Spire 2?: Compare the upgraded text: Cost changes from 1 to 0. If the upgrade lowers cost, adds damage/block, or enables a combo piece, it is usually high priority.
What builds use Subroutine?: Subroutine appears in 2 tracked builds: Storm Conductor (S-tier, flex pick), Machine Mind (B-tier, core card).
What character uses Subroutine?: Subroutine is tagged as a Defect card. See the Defect build hub for archetypes that care about it.

Patch history

SpireForge snapshots card text from Untapped exports dated 2026-03-17. When Mega Crit ships a balance patch, we re-run the scraper and refresh every affected URL—see /patches for the editorial log.