Correlated randomness in Slay the Spire 2 - Andy Tockman
https://tck.mn/blog/correlated-randomness-sts2/
Briefly, in Spire 1, the game used several distinct pseudorandom number generators, to prevent e.g. randomness within a combat from influencing future card rewards. However, they were all initialized to the same starting state, which meant they produced the same sequence of numbers. A crafty player could therefore pay attention to the results of past random events and gain information about future random events.