The rule could be anything, as funny or as serious as you want. The universe will progress in a similar way that it has up until this point, unless your changed rule prevented it from doing so.
Some examples might be:
- The invention of currency is not allowed.
- Iron is slightly less stable.
- The Ancient Greeks are able to cultivate Silphium, which does not go extinct now.
Yeah I was just teasing you. That actually seems like one of the more fun ones here… Though there’s some frightening implications.
Haha thanks :)
And yeah, this could probably quickly either wipe us out (along with possibly everything else) or help us flourish (along with the rest of the world)