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.
  • TheChargedCreeper864
    4·
    18 days ago

    Any and all personal gain becomes mutual gain.

    • If you don’t intend to cheat anyone, the party you’re interacting with gains in a similar “amount” as you
    • If you achieve personal gain at the cost of someone else, their net gain will be even greater than yours
    • In case there’s no direct party you’re interacting with while gaining (such as you running a red light when no one’s around to be inconvenienced), society as a whole gains