Rules:
- History of the world before your birth remains the same; only events happing after your birth can be changed.
- The other version of you must still be alive, you cannot go to a world that you are dead in. (This essentially forces you to murder/abduct your alt-self, so travelling has a ethical cost to it 😉)
- There may be other multiverse travellers out there
(Btw, is it ethical to murder an alternate version of your self? Is that even murder or just self-harm technically?)
This. I don’t understand why murdering your alt-self is “necessary”. Wouldn’t you actually want to preserve your alternate-self at all costs, to ensure you can continue to make return trips?
The real issue here is that - if your home reality works by the same rules - once you leave it, you can never return home ever, because no alternate version of yourself exists in the one you originated from after you leave it.
Before you say “hey, that sounds awesome, this place sucks!”, consider that finding a better reality is not guaranteed.