Should I upgrade Signal Boost 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 Signal Boost?

Signal Boost appears in 1 tracked build: Machine Mind (B-tier, core card).

What character uses Signal Boost?

Signal Boost 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.

Signal Boost

Defect · Skill · Rare · 1 cost

Base

Upgraded

Card text

The next Power you play is played an additional time. Exhaust.

Signal Boost+

Cost changes from 1 to 0

Builds that use Signal Boost

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

BMachine MindDefect · Core card

Keywords

Exhaust

Build context

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

Related cards

Signal Boost FAQ

Should I upgrade Signal Boost 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 Signal Boost?: Signal Boost appears in 1 tracked build: Machine Mind (B-tier, core card).
What character uses Signal Boost?: Signal Boost 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.