There never were, since the creation of the world, two cases exactly parallel.

Discussing the barest minimum of Mass Effect 3 details with m’colleague, lest either of us introduce the other to a spoiler and spontaneously combust as a result, we realised that our games had diverged over the course of the trilogy, and that having a meaningful discussion without spoilers was precluded by the fact that the foundations of our ‘universes in peril’ had surprisingly little common ground, outside of the main plotline at least.

Of course it quickly brought to mind the old topic of ‘static versus dynamic worlds’ with respect to the multiplayer experience, such as in MMOs, where games such as Ultima Online and EVE Online took the fine decision to make their game a framework of tools, tools which enable the most dynamic of all possible content –the players– to be the content for one another.

NPCs in my game, whom I love and indeed have loved, are entirely absent from m’colleague’s parallel sphere of existence, a situation over which my Shepard would give his Shepard a stern rebuke, if only she could find a way to travel between parallel universes. Alas, it’s in yet another universe entirely that humanity has discovered how to travel between different universes. And anyway, as soon as you leave your universe, that universe ceases to exist because an intrinsic part of it has been removed, meaning it could never have existed in the first place. Of course when *that* happens, *you* cease to exist, because your originating universe never existed, and thus you could never have existed. Which of course means that your universe could exist, because you never existed to leave it, so it pops back into existence. Along with you. Whereupon you find yourself on the point of leaving the universe and… oh dear.

And so without dynamically generated content, it’s quite the conundrum as to how to let different players experience the same content, within the same world, without introducing a paradox, or at least people getting into terrible fights.

Player 1: “Have you met NPC Geoff? This is NPC Geoff, one of my most loyal followers.”
Player 2: “How can that be? NPC Geoff is DEAD, I sacrificed him in order to save NPC Foxabella”
Player 1: “NPC Geoff is NOT dead!”
Player 2: “Yes. He is.”
NPC Geoff: “I, uh, I’m not. Right here.”
Player 2: “Yes you ARE [stabs]”
NPC Geoff: “Okay, now I am. Urk…”
Player 1: “No you’re NOT [casts Resurrect]”
NPC Geoff: “Well fi…”
Player 2: “ARE! [stabs]”
NPC Geoff: “Ow…”
Player 1: “ARE NOT! [casts Resurrect]”

And as for the ‘which NPC slept with which PC and when’ situation… awkwarrrrd. I mean, giving another playing character an accidental rogering due to an entangled NPC paradox causing your two timelines to intersect momentarily (and my what an intersection!), is the stuff that really bad fan fiction is made of.