GoKawiilCorrelated randomness in Slay the Spire 2 2026-06-13
Here are three true statements about the game of Slay the Spire 2 (in single player):
If you pick Neow's Bones in the Underdocks, the random curse is ~54% likely to be Debt.* It is impossible to receive Rebound from the Trash Heap event. Your first fight is 76% likely to drop a potion in Underdocks, and 4% likely to drop a potion in Overgrowth.**
(* assuming neither of the relics from Neow's Bones is New Leaf or Kaleidoscope)
(** assuming your Neow relic doesn't give cards or other relics)
(*** all on the current beta patch, v0.107.0)
What?!
Why? The culprit is unexpected correlation between different random number generators -- knowing the first output of one of the game's RNGs gives information that helps predict the first output of all of the others.
The random number generators of Slay the Spire 2
For now, I will give an extremely simplified explanation of this correlation. If you want more details, I will go into much greater depth at the end of this post. If you don't care, you can skip this section to see all the funny examples below.
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