Bosses

Slay the Spire bosses guide

Looking for reliable strategies to beat Slay the Spire bosses? This guide summarizes common patterns, lethal breakpoints, and route planning tips for every act. Whether you're climbing on Ascension 20 or learning the game, understanding boss intents, scaling windows, and when to defend or race is the fastest way to consistent wins.

Act 1 bosses: Hexaghost, Slime Boss, Guardian

• Hexaghost: Count the opening multi‑hit; plan block on turn one. Vulnerable and Weak are premium.
• Slime Boss: Burst damage to split at safe HP thresholds. Multi‑hit cards and potions shine.
• Guardian: Shift between attack and defensive mode; play skills to trigger stance safely, then punish.

Act 2 bosses: The Champ, The Collector, Bronze Automaton

• The Champ: Save Weak and artifact strip for the Execute phase. Don't over‑scale early.
• The Collector: Control adds with AOE; target the boss when candles are down.
• Bronze Automaton: Reclaim stolen card quickly; AOE for orbs, single‑target for the body.

Act 3 bosses: Time Eater, Awakened One, Donu & Deca

• Time Eater: Play in 12‑card cycles; bank energy/cards for burst turns.
• Awakened One: Powers give it Strength—counter with Artifact removal or fewer powers.
• Donu & Deca: Kill an obelisk quickly to reduce scaling; do not split damage.

Act 4 boss: The Corrupt Heart

The Heart checks damage, scaling and consistency. Plan for Beat of Death, multi‑hit turns, and artifact for debuffs. Potions like Potion of Steel, Dexterity, and Focus can swing the fight.

General boss tips

• Use boss intents to route turns and avoid surprise spikes.
• Draft consistent damage plus enough block to cover scripted big hits.
• Prioritize relics and cards that answer your weakest axis (damage, block, scaling, sustain).
• Plan rests and upgrades around the expected boss; e.g., upgrades that change breakpoints.