I swear this is a thing, but I’ve not intoned the proper keywords into the documentation. Is there a way for “Replay” in the IDE to exactly recreate the last sequence, with random chances playing out the same and everything?
The first thing to look at is maybe Writing with Inform 8.18 Randomness. It discusses the IDE setting to make random number generation predictable.
For a testing build, there is also the >RANDOM command. Issuing this command first in the running story will set the RNG seed. You can provide a specific seed via >RANDOM 123 or whichever you like.