Version ledger / bosses
A Boss name is a version stamp.
Updates can swap a Boss out or change how an encounter plays. This page keeps the current roster separate from historical names so an old strategy never passes for current advice.
At a glance
The roster in four answers
| Question | Current answer |
|---|---|
| Current Act 3 boss | Aeonglass, in the game since Major Update #2 (v0.107.1, June 19, 2026) |
| What happened to Doormaker | Historical entry: the v0.107.1 update swapped the encounter, so guides written against the launch build or Major Update #1 name the old fight |
| Does the same name guarantee the same fight? | No. An update can change an encounter’s attack pattern even when the name stays the same |
| Where the record stops | Beta v0.111.0 (August 14, 2026); past this label, a change claim is unverified here |
| Entry | Detail | How to use it |
|---|---|---|
| Version boundary | Aeonglass arrives with Major Update #2 (v0.107.1, June 19, 2026) | Prepare the fight the version you run actually puts in front of you. |
| Historical name | Doormaker belongs to the roster before v0.107.1 | Keep the name as history; do not plan a current run around it. |
| Pattern notes | An attack pattern with no version label has no way to show its age | Find the update a note names before you trust a turn plan. |
Preparation
Four checks before trusting a Boss plan
| Check | What to confirm | Why it matters |
|---|---|---|
| Roster | Confirm which Boss is actually in the current build | An old name sends you toward an old plan. |
| Version label | Check the update that changed the encounter | A patch can swap a Boss or its attack pattern. |
| Deck answer | Name the specific threat your deck must answer | A generic build slogan does not prepare the fight. |
| Turn plan | Reserve a plan for the encounter's key turn | Preparation beats memorizing a fixed rotation. |
Run structure
Where boss preparation fits in a run
The checks above are not a study plan; they happen at specific moments of a run. This is the sequence, from committing to a build to re-checking after the next update.
| Moment | What happens |
|---|---|
| Before the run | Fix the build label you are playing (default or beta branch). Boss advice written against one branch can describe an encounter the other does not contain. |
| Act 1-2 route | Pools and stakes move between Acts, so a mid-run deck is already being shaped by the boss it is heading toward. The map page covers the route choices that set it. |
| Approaching Act 3 | Confirm which boss the current build actually puts at the endpoint; since v0.107.1 that is Aeonglass rather than the Doormaker fight older guides describe. |
| The encounter | Name the specific threat your deck must answer and reserve a plan for the encounter’s key turn. Scaling values are sized by party size in co-op, so block and damage plans are group arithmetic there. |
| After an update | Re-check the roster and any pattern note you kept. A name that survived an update can still describe a different fight. |
FAQ
Boss roster questions
Which Slay the Spire 2 Bosses changed between updates?
Major Update #2 (v0.107.1, June 19, 2026) brought Aeonglass in as the newest boss encounter. A note that still describes the earlier Act 3 fight is a pre-v0.107.1 roster.
Why do some Boss lists still show Doormaker?
Because they were written before the change and kept the old name. Doormaker is a historical entry here; Aeonglass is what the updated build brings. The fix is the same for any boss note: find the version it names, or treat it as a guess.
How do I prepare for a Boss without guessing?
Confirm the current roster and version first, then name the specific threat your deck must answer and reserve a turn plan for that threat. Do not rely on an old name or a memorized rotation.
Does a Boss name guarantee the same fight?
No. An update can change an encounter's attack pattern even when the name stays the same. Match your plan to the current build.
Why keep historical Bosses on the page at all?
Historical entries explain why older guides conflict with the current game. Keeping them labeled prevents a stale name from becoming bad advice.
Version changes ripple outward
A Boss swap touches route planning, deck answers, and multiplayer encounters. Trace the change in the patch ledger before you rewrite a strategy.
Last updated: August 27, 2026 · Version boundary: Beta Patch v0.111.0 (August 14, 2026)