[kungtotte]

John Carmack has some ideas on how to use immutable copies of the game state and functional programming concepts to create something that's easily parallelized. I saw it in an old QuakeCon keynote: https://youtu.be/Uooh0Y9fC_M

[jfkebwjsbx]

Duplicating state has always been an approach for multithreading, but the problem is that it is not always fast enough and merging back can be hard.

There is no silver bullet. There are decades of academic research and engineering on this and we have yet to reach a good answer.