Last week I watched the Director’s Cut of Donnie Darko for the first time, ten years after watching the theatrical release. For those interested in my opinion, the latter had a problem: the plot was a little too convoluted to be left at that. The DC, on the other hand, tries to remedy in a distinctly uncinematographic way: by adding long text excerpts that the audience is expected to read and put together. So, neither is entirely satisfactory, but I still like the mystery and the conciseness of the older cut above the expository excesses of the DC. Anyway, the film induced some disordered thoughts about time travel in fiction and RPGs.
There are basically three “cool things” about time travel that just about define its place in fiction. First, I will call the Theme Park Effect. Imagine yourself fighting in a Roman legion, serving at the court of a Chinese emperor, or meeting dinosaurs: how cool is that? This appeal is pretty self evident, but also quite superficial (hence the name). This happens to be pretty much included in all time travel RPG settings.
Second, the “What If” Effect. This involves the notion of (alternative) presents, rather than times in the past. The relevant scenario is when some time traveler changes something in the past which either changes their own present or, in some conceptions, creates a brand new timeline which differs from their original one. This is much more sophisticated than the first aspect, and presupposes more complex problems. In fact, it might even involve one or more of the following…
Third, the Paradoxes. I will not go into the devilish subtleties of time travel. By Paradoxes, I refer generically to all the sort of counterintuitive causality related problems involved in time travel to past times. Even occasional fans of SF know those: What does it happen if you meet your older self? What if you kill your grandfather? etc. In fact, SF literature (and, nicely enough, the academic philosophical literature) has a range of formulations of this strand of problems and a good number of different solutions (never mind the fact that, by the most rigorous definition, if something can be solved it was no paradox to begin with).
The problem, simply put, must be that paradoxes are a mess, and more specifically, a GM’s nightmare. Imagine having to detail how a given PC’s actions in the past are going to modify their original timeline. What happens? Does it affect their original timeline, when he or she comes back to the present? Or is it a Multiverse reality, so that one change just create a parallel timeline alongside the original one? Even if the latter is the case, how can the PCs manage to get back to their own universe, as opposed to find themselves in a new “future”? So it is not that strange that RPGs, mostly, discourage the inclusion of Paradoxes in your game.
These days I have browsed through two (absolutely likable and intriguing) settings, one for Fate Core (Timeworks, in Fate Worlds 2: Worlds in Shadows), another one for GURPS (first as a suggested campaign for GURPS Time Travel, then as an assumed background to GURPS Alternate Earths 1 & 2, then as the 4e standalone volume Infinite Worlds). They are remarkable in that they manage to incorporate all of the superficial glamour of the Theme Park Effect, and even to give you some of the mind blowing appeal of the “What If” Effect, but without allowing for real Paradoxes. Let us see how.
Timeworks circumvents Paradoxes in two ways. First, the opposite of the Butterfly Effect is claimed to be true: minor changes in the past do not propagate or snowball. The effect of a change in the past is always minimal (the timestream is “inertial”, so to speak). This is still fine, because the assumed task of the PCs is always to induce local, limited changes on behalf of private clients (say, make so that a certain work of art is inherited by my family, or that I win that academic prize etc.). Second, Paradoxes involving the PCs themselves (say, if they kill their grandparents) are avoided because they undergo a process called “dealignment”, by which (preemptively) they are causally disconnected from the current timeline: they are ontologically zeroed, their existence is written off. This, in itself, is only a drastic measure to make Paradoxes literally impossible, but it lends itself to bringing an existential angst component in the game that might be appealing to many players.
The older setting, Infinite Worlds, is a more complex affair to begin with. It is not, strictly speaking, a time travel setting, but it is built in such a way that it shares much of the appeal of time travel, minus the Paradoxes. The Theme Park Effect is offered by worlds called Echoes: worlds which are like our own at a given point in the past. Since these are not our past, changing them has no effect on our future (even though it is discouraged anyway, for setting specific reasons). The “What If” Effect is served by another type of worlds, Parallels: these are worlds which resemble how our world would have been, had certain things been different at a given point in the past (divergence point). Interestingly, it does not seem to be the case that Parallels result from changes occurred to Echoes: all in all, this ontology feels a bit contrived, because it was pretty clearly invented by the authors in order to mimic the best time travel fiction pretty closely, while at the same time preventing Paradoxes. Interestingly, the latest iteration of the Infinite Worlds campaign (the 4e volume) retains a (now) pretty unjustified chapter on real time travel, which goes at length about why it is a bad a idea for a GM.
How shall I conclude? First, that even Paradox-free time travel (or analogous notions) makes for an attractive premise for an RPG adventure or campaign. Second, that I would be curious to read an RPG that takes time travel more literally and makes Paradoxes the core of the setting: does anything like that exist? Let me know.