Underdocks
Soul Fysh
Manage Beckon without destroying your Energy and draw quality, avoid wasting major damage into Fade, and prepare for the attack after Scream.
Status Intangible Timing
HP
211
Asc.
221
Moves
5
Slay the Spire 2 Boss Guide
All 12 Slay the Spire 2 Bosses
Start with the Boss your run is actually heading toward. Each guide focuses on the decision that changes the fight: what your deck needs, which turn matters, what to kill first, and when normal card value changes because of the matchup.
12 Boss Guides
3 Acts
12 Decision Owners
Main v0.107.1
Quick Answer
What Should I Check Before the Next Boss?
Do not ask only whether your deck is strong enough . Ask what the next Boss specifically punishes. One fight may test frontload, another may test card access, another may require a precise kill order, and another may punish your strongest damage card if it arrives on the wrong turn.
This Hub keeps one strategy Owner for each Boss encounter. Open the relevant guide below, identify the matchup weakness, then use Card Picks or the Deck Evaluator if the deck still needs an adjustment.
Boss Strategy
Act 1 Bosses
Overgrowth · Underdocks
6 Guides
Do not prepare for every possible Boss in the same way. Open the fight you are actually approaching and check the one mechanic that can force a card pick, potion hold, rest, damage threshold, or different turn sequence before the end of Act 1.
Underdocks
Waterfall Giant
Kill fast enough to control Steam Eruption, but do not take lethal until you know how the deck survives the post-kill explosion.
Kill Timing Explosion Defense
HP
240
Asc.
250
Moves
8
Underdocks
Lagavulin Matriarch
Turn the three sleeping turns into meaningful scaling, then finish before repeated Soul Siphons make ordinary Attacks and Blocks too weak.
Sleep Scaling Debuffs
HP
222
Asc.
233
Moves
5
Overgrowth
Vantom
Strip Slippery with repeated damage instances before spending your largest attacks, then reserve enough defense for Dismember.
Slippery Multi-Hit Dismember
HP
173
Asc.
183
Moves
4
Overgrowth
Ceremonial Beast
Race the first phase to the transition threshold, then solve the Ringing Stomp with one dense defensive card instead of several small plays.
Phase Race Ringing Frontload
HP
252
Asc.
262
Moves
6
Overgrowth
The Kin
Reduce enemy count immediately by killing the Followers, survive the early Frail pressure, then handle Kin Priest as the easier solo fight.
Minions Frontload Multi-Enemy
HP
190 + 2×58–59
Asc.
199 + 2×62–63
Moves
3 enemies
Boss Strategy
Act 2 Bosses
Hive
3 Guides
Do not prepare for every possible Boss in the same way. Open the fight you are actually approaching and check the one mechanic that can force a card pick, potion hold, rest, damage threshold, or different turn sequence before the end of Act 2.
Hive
Knowledge Demon
Route each Curse of Knowledge around the resource your deck can afford to lose, then switch to a damage race after the third curse.
Curse Routing Draw Energy
HP
379
Asc.
399
Moves
4
Hive
The Insatiable
Use cheap Frantic Escapes to buy time early, then stop preserving every Escape once second-cycle Status pollution becomes the bigger problem.
Sand Pit Status Draw Quality
HP
321
Asc.
341
Moves
5
Hive
Kaiser Crab
Control facing, usually remove Rocket before repeated Laser checks, and never trigger the survivor Strength bonus without checking the next intent.
Facing Kill Order Multi-Enemy
HP
209 + 199
Asc.
219 + 209
Moves
2 enemies
Boss Strategy
Act 3 Bosses
Glory
3 Guides
Do not prepare for every possible Boss in the same way. Open the fight you are actually approaching and check the one mechanic that can force a card pick, potion hold, rest, damage threshold, or different turn sequence before the end of Act 3.
Glory
Aeonglass
Use the setup window to establish a real engine, then make sure that scaling can actually convert into damage before the fight outpaces your deck.
Setup Scaling Consistency
HP
512
Asc.
535
Moves
3
Glory
Queen
Remove Torch Head first by default, keep functional card access through Bound, then finish Queen before Strength-scaled multi-hits become unmanageable.
Bound Minion First Multi-Hit
HP
400
Asc.
419
Moves
6
Glory
Test Subject
Solve three different fights in sequence: Phase 1 frontload, Phase 2 escalating multi-hit damage, then Phase 3 Intangible timing and Burn consistency.
3 Phases Intangible Consistency
HP
Phase-based
Asc.
111 / 212 / 313
Moves
7
Run Planning
What Should My Deck Solve Before the Boss?
A strong deck does not need every answer. It needs enough damage, defense, and card access to survive the exact mechanic that can end the current run.
Check 01
Front-loaded damage
Can your deck end an urgent phase, remove a minion, or delete a dangerous target before slow scaling becomes a liability?
Check 02
Reliable defense
Can you survive the fight’s real danger turn, or does your Block only work when several ideal cards arrive together?
Check 03
Scaling speed
If the Boss fight lasts, does your damage or defense improve quickly enough to keep pace with healing, Strength, Status cards, or repeated phases?
Check 04
Card access
Can you find the important Block card, payoff, Weak source, retained card, or setup piece on the exact turn where the fight needs it?
Check 05
Status and debuffs
Will Burns, Wounds, Beckons, Frail, Weak, Bound, or another mechanic break the turns your deck normally depends on?
Check 06
Potion assignment
If one turn is especially dangerous, decide before the fight whether a potion is covering that turn instead of spending it casually earlier in the Act.
Version Intelligence
Main and Beta Boss Data Stay Separate
The strategy layer should not silently mix two versions of the game. Current Main data is v0.107.1 while the current Beta branch is v0.111.0 . HP, move values, Powers, and the resulting matchup judgment can be reviewed separately when Beta changes matter.
Boss Questions
Slay the Spire 2 Boss FAQ
Should I draft a card only because it is good against the next Boss?
Only when the card fixes a real weakness in your current deck. A matchup card is valuable when it changes an otherwise dangerous turn or phase, but weakening the rest of the deck for a narrow counter is usually unnecessary if your existing engine already solves the fight.
Is Boss HP more important than the attack pattern?
Usually not by itself. HP tells you how much damage the deck eventually needs, but the decisive question is often whether you can produce that damage before a specific phase, scaling loop, Status problem, or large attack becomes dangerous.
Why are Kaiser Crab and The Kin shown as one Boss guide instead of separate enemy guides?
They are multi-enemy Boss encounters. The strategy depends on kill order, simultaneous intents, and encounter-level mechanics, so one Owner guide is more useful than splitting the same fight across separate strategy pages.
Is a deck that beats Elites automatically ready for the Act Boss?
No. Elite fights often reward immediate tempo, while Bosses can test a different weakness such as sustained scaling, one-turn defense, card access, Status handling, multi-target control, or damage timing.
Should I use Main or Beta Boss information?
Use Main data when playing the current live Main branch. Beta information is kept separate because HP, moves, Powers, and matchup judgments can change before a Beta update reaches Main.