Upgrade Priority Cards

Choosing which cards to upgrade at campfires is one of the most important decisions in Slay the Spire 2. With limited upgrade opportunities — typically 4-7 per run — selecting the right cards to upgrade can significantly impact your success rate. This category highlights cards whose upgrades provide the most value.

Upgrades generally fall into three categories: numerical improvements (more damage, more block), mechanical improvements (reduced cost, added effects), and enabling upgrades (turning a good card into an excellent one). The best upgrades are those that change how a card functions, not just by how much.

Cost reduction upgrades are among the most valuable. Cards like Corruption and Wraith Form that cost 3 energy become much easier to play when upgraded to cost 2 or retain. Upgrades that add card draw or generate additional resources also provide outsized value, as they improve your deck's consistency as well as individual card power.

Each character has priority upgrade targets. For the Ironclad, upgrading Bash (3 Vulnerable instead of 2) is almost always correct. The Silent's Survivor upgrade (+3 block) and Neutralize upgrade (+1 Weak on application) provide excellent early-game value. The Defect's Zap upgrade (Innate) and Dualcast upgrade (+damage) are high priority.

Consider your deck's specific needs when upgrading. If you lack AOE, upgrading a Whirlwind or Electrodynamics may be better than upgrading a single-target card. If you're struggling with defense, upgrading your best block card may be the right call.