Practical Verdict
What changed, in one sentence
The generator changed; the idea of a deterministic seed did not. Current runs remain repeatable, while old outcome maps must be rebuilt against the current version.
Current Seed Behavior
Slay the Spire 2 RNG and Seed Guide
Displayed seeds now use 12 letters and numbers. The same seed still creates a repeatable run, but old seed tables and prediction methods may not describe current results.
Record the full 12-character seed and the game version together. A route, reward, or Neow outcome saved without both details is not a reliable forecast for the same run today.
Change pointv0.107.1
Current PRNGxoshiro256**
Run seed12 letters and numbers
Daily statusCurrent runs stay comparable
Reviewed for v0.109.0 · July 19, 2026
Current Format
Copy all 12 seed characters
Current displayed seeds are 12 characters long and use letters and numbers. The larger internal seed space does not change how a player enters or shares a seed; it only makes the complete 12-character value essential.
Do not trim leading characters or reuse notes that record only part of the displayed value. For a reproducible test, save the full seed, version, mode, player setup, and the decisions that advance each random stream.
Version Boundary
Old seed tables stop at v0.107.1
Before v0.107.1, separate random streams could show unwanted correlation. Knowing an unrelated early result could narrow a later outcome more than intended.
The current generator removes that useful cross-stream shortcut. If a seed sheet, predictor, or route note was recorded on an earlier version, treat its concrete outcomes as historical rather than current.
What Persists
A current seed is still deterministic
A run starts from one displayed seed, then derives separate streams for different jobs. Repeating the same seed on the same version with the same decisions should reproduce the same sequence.
That does not mean every visible outcome is fixed in isolation. Actions that consume a random result can advance one stream, so changing a choice may change later results within that same stream.
Daily Challenges
The scoring tool does not predict RNG
The Daily Challenge Score Calculator compares result state, floors, badge count, and finish time. None of those calculations depend on the random number generator, so its ranking logic is unchanged.
Route predictions are a different matter. Use only notes recorded on the current version, especially when comparing events, rewards, shops, or opening outcomes.
Separate Streams
What the run seed feeds
The run does not pull every decision from one shared queue. It keeps distinct streams so unrelated systems do not need to consume the same sequence.
Run setup
- Monster lineup
- Event lineup
- Relic offers
Map and combat
- Unknown room rolls
- Draw-pile shuffles
- Monster move choices
- Random targets
Player results
- Card and potion rewards
- Shop inventory
- Transformations
Generated effects
- Cards created in combat
- Potions created in combat
- Random Orb generation
Before Trusting A Prediction
Four checks that prevent bad comparisons
Check the version first
If the note predates v0.107.1 or has no version label, do not use it as a current prediction.
Match the mode and player setup
Solo, co-op, and Daily Run contexts can consume results differently. Compare like with like.
Repeat the same decisions
A different choice can advance a stream at a different time. A seed match is not enough if the action history changed.
Separate scoring from route prediction
Leaderboard sorting still uses the run result. RNG changes affect route forecasts, not the score comparison order.
FAQ
Seed and Daily Run questions
How long is a current Slay the Spire 2 seed?
Current displayed seeds are 12 characters long and use letters and numbers. Copy the complete value and keep it with the game version when sharing a route or result.
Does the same seed still produce the same run?
Yes, when the version, mode, player setup, and decisions match. Changing an action can advance a random stream differently and alter later results.
Can I use a seed guide made before v0.107.1?
Use it only as a historical reference. Concrete routes, rewards, shops, events, or opening outcomes should be rechecked on the current version.
Did Daily Challenge scoring change with the new generator?
No. The leaderboard comparison still uses result state, floors, badge count, and finish time. The generator change matters for run outcomes and prediction methods.
Why can two attempts with one seed diverge?
Different choices may consume results from a stream in a different order. Version, mode, player slots, and action history all need to match for a clean comparison.