Combat Undo

StS2 Undo

Take it back — undo card plays and turns during combat

StS2 Undo lets you reverse a card play, a potion use, or an entire turn

during combat in Slay the Spire 2. Misclicked a card on the wrong target?

Played a Power before drawing? Burned a key potion at the wrong moment?

Press Z and the combat snaps back to the moment right before that

action — HP, block, energy, draw/discard order, monster intents, RNG,

animations, and all.

On the STS2 beta branch?

This file (Sts2UndoMod-v0. 0. 12.zip) is the

stable-branch build. If you have opted into the STS2 beta in

Steam (right-click Slay the Spire 2 → Properties → Betas), grab the

beta-branch build instead — open the Files tab on this mod page

and download Sts2UndoMod-v0. 0. 12-beta.zip from

there. Running this stable dll on the beta branch (or vice versa)

throws MissingMethodException at the first

card play because the STS2 API changed between branches.

The two files exist only because STS2 currently has two parallel public

branches with a small API difference. Once STS2 promotes v0. 104. 0+ to

its public stable branch, this stable file will be re-released against

the new API and the two files will collapse back into a single

download. If you don't run beta opt-in, this is the only file you

What pressing Z does

• []Single-step undo — pops the most recent snapshot and restores the

  exact combat state at the moment before the last card / potion /

  end-turn was played

  []Turn-level undo — Shift+Z rewinds all

  the way to the start of the current player turn in one go

  []In-combat undo button — a ↶ Z button

  appears next to the energy display; clicking it does the same thing as

  []Combat-only — the undo system is active inside an active

  combat. There is no undo on the map, no undo after a death animation

  finishes, and no undo across screens

  []30-snapshot history — up to 30 prior states per combat are kept

  in memory; older snapshots are dropped silently

How it works

The mod takes a deep snapshot of the combat state the moment any of

these actions begin:

[]Card play (PlayCardAction)

[*]End turn (EndPlayerTurnAction)