Realistic Time Travel

[Oracle_Hunter]

Which really only works in a more spiritual setting.

I suppose, although you can simply apply the "elastic history" principle and not call it "reincarnation" if that floats your boat

Another problem with multiple universe from a gaming perspective is you need to be inhumanly good at improvisation and figuring out plausible consequences. Unlike a science fiction story, where you only need to plan as many 'branches' as appear in the story, and the actions that created them, players always do the unexpected thing.

Helpfully, if the DM can't easily foresee the consequences, then neither will the Players. Who can say with authority what blowing up a cotton warehouse in 1850 will do to the 1996 we know and love? In a game setting, it is the DM - and he can pick and choose any of the various Butterfly Effect modifiers he likes to have it turn out however he prefers. Sure, the Players can do more to try and "fix" history but when you use San Dimas Time you have a limited ability to perform "do overs."

Additionally, you can make the influencing of Key Events part of the system. Perhaps only a few things actually do matter in the grand scheme of things. In Feng Shui these sites are known in-game and manipulating them is a major driver of the action. For the DM, this makes the suite of probable multiverses somewhat smaller.