Although TTU -- an urban fantasy setting, based on a modern Earth where magic and creatures of fantasy/myth/anthropomorphics suddenly turn up after a dragon walks through a news broadcast in the closing days of 1996 -- is of interest mainly to me and my fellow universe collaborators, I think the broader question is a pretty interesting one in general. When you're pulling a world setting into a role-playing game, what system works best, and why?*
This is obviously going to be very different for different worlds. A superhero setting, a cyberpunk setting, a horror setting are all going to have very divergent focuses, and the roleplaying genres built up around each theme tailor themselves to those themes in ways that help create expectations and a mood. It was with this in mind that I tried to dig down to the foundations of the question.
No matter what setting you're trying to adapt, I think there are two big issues:
- whether you have a cinematic (bigger-than-life heroes vs. long odds) setting versus a gritty, more dangerous (and more "realistic," in that the hazards characters face are more appropriately lethal) one;
- and whether the heroes/PCs have access to significant power without the constraints of a rigid rule system that shoehorns it into specific categories of use ("high-chaos") versus whether the setting offers predictability, a given set of powers that do exactly what they're said to do ("low-chaos"). In the original reply, I used "high-magic" and "low-magic," but that doesn't quite have the ring -- I'm trying to capture the flexibility of the power characters have to alter their environment; how much power people in the setting have to pull the unexpected out of their nether regions.
My view as an author is that TTU is a gritty, high-chaos place. Magic has many subtle direct effects and a very powerful social secondary effect; it doesn't blow apart buildings or brainwash cities at a leap. And individual mages are putting themselves very much at risk in a way that cinematic systems don't really account for. ("Oh, man, I just took 44 points of damage. Hand me a healing potion, willya?")
If I personally were going to GM a TTU game, I would probably cobble something together starting from the basis of the GURPS-system "Mage: The Ascension" adaptation. Low-character-point GURPS games are grit personified, and work well in concert with the high-chaos Mage system.
If you want cinematic high-chaos, my opinion is that the original Mage: The Ascension (the game that defined high-chaos, to the eternal regret of headachey GMs everywhere) is the way to go.
Cinematic low-chaos might work well with d20 -- although I really dislike the AD&D "level-based" magic system, so in settings which include magic or magic-equivalent powers, IMHO characters should be mostly non-mage types. If I were to run TTU in a low-chaos game -- with characters who were theris but not mages -- I would personally seriously think about giving Ironclaw a modern-day overhaul. Also, the vast majority of "superhero" genre games slot here -- along with, I suppose, most RPGs in general. (For TTU, superhero games have the advantage of being already set in the modern era.)
Gritty low-chaos, depending on the setting's genre and the level of grit, might see anything from Call of Chthulu on up. Generic systems like GURPS (which I like, sorry
];=8)) and HERO, though complex, offer high grit factors and flexible genre.
I'm sure there are many good games I'm neglecting. I invite your suggestions for games that lend themselves well to setting adaptations, or tales of how your setting of choice translated into an RPG.
* Amusingly, I tackled the reverse question -- putting a role-playing game into a world setting -- long before I thought about this. TTU has its own imaginary roleplaying system, "Age of Ascension," which some people might say is cribbed from a very similarly titled game but I have no idea what they're talking about. *innocent look* It's got a standard high-fantasy genre setting, uses buckets of six-sided dice, and is set in an era where humanity is growing into its power and seizing the reins of magic in order to tip the balance from being minority-race-in-threatening-world to dominant-powers-threatening-extinction-o