What game system to use?

We talked a bit about my time travel via reincarnation campaign idea that Siobhan intends to run at the final session of our Committee for the Exploration of Mysteries game, but we didn't settle that many of the pending questions. One of those is the question of what system to use.

Arguably my two roleplaying game systems, RTC and Prism, occupy opposite ends of the spectrum between simple and complex (or what people usually mean when they say those things about RPGs). Probably neither of them is right for this game.

Prism is too cumbersome for a game where you're going to be redefining your skills in some ways every adventure. You could make it work but all that complexity wouldn't be buying you that much. Probably the best way would be to make it so you had some number of development points that were permanently spent for your "present day" character, and then a pool you could spend on top of those every time you started an adventure, for whatever is added by that particular life, but you wouldn't lose anything you already had. I think this could be made to work but it'd be a strain. First, any number of points for your flexible pool would be too much and not enough; it'd be too much since it'd make it too much work to prepare for an adventure, and not enough to reflect all of your past life's skills. Second, even using the character spreadsheet, it'd take too long. And you wouldn't gain enough from this for it to be worth it.

RTC might be too skimpy. It's one thing to use it in a fixed, well-understood setting like the real world, where we can assume that the GM and players will largely be on the same page about how difficult tasks are, or what outcomes to expect from an action, or what a person of a particular skill level would know. In that situation, the ambiguity and vagueness is no obstacle. But even assuming you were able to make some small adjustments between your present-day and past-life characters, the differences wouldn't really tell us what your past life knows about the religion of his native ancient Egypt, how to make barrels, the current state of various noble houses in Florence, which dialects of Demotic he can translate, or how comfortable he is with the Swiss pike. In the end you'd be too much the same each time.

One idea for how to address this is for me to make a tweaked version of RTC with a bit more detail thrown in. First, I'd increase the number of specializations you could have, and some would be redefined in each world. Thus, the amount of work you're doing at the start of each adventure is really nothing more than writing down a list of things your past life knows -- the same thing you'd be doing if you did this free-form, really. Second, I'd come up with some rules for a new flavor of token-spending similar to, but distinct from, plot twists. These tokens would represent as-yet-unspecified past life knowledge or resources; you'd get a bunch at the start of each adventure, and then spend them to "remember" that your character's past life knows something, or has something. Examples would be "Oh, I remember I learned how to tie that kind of knot when I was working for a sailor in the French Navy," or "I think I stashed a spare ingot of copper just like what we need behind the anvil in my forge," or "Actually, I recall the Duke owes me a favor because of that indiscretion of his daughter's that I kept to myself." You could make these up on the spot as you needed them, so they'd be like plot twists, but they'd always take the form of past-life backstory, not a present event; and you'd have a strictly limited number of them. In essence, half the "redefine your character" stuff would be something you'd put off and do in play.

The latter approach seems more promising, and I will probably spend a little time trying to write up those rules. However, it's possible the best approach is to use neither system and instead use one of the countless, and often very good, systems that already exist. I just need some ideas on what it would be -- and then, I'd need Siobhan and me to get familiar enough with it to do the game development and then play it. Anyone have suggestions?