There's a whole section of the gaming industry devoted to games based on established properties such as movies, books and tv shows. I think it's fantastic, because not only do gamers get to jump straight into playing in their favourite worlds without trying to adapt another system, but it also draws newcomers to the hobby who are fans of the property in question.
One of the earliest properties to be licensed for a roleplaying game, and still one of the more popular ones today, was Star Wars. Originally published by West End Games, there have been four different versions of the roleplaying game produced over the years and my time running Star Wars campaigns have given me some of my fondest gaming memories. To this day, I hold that my most successful campaign ever was a two and a half year Star Wars game which spanned from shortly after the destruction of the first Death Star to the years following the fall of the Empire and the rise of the New Republic.
Ghostbusters, Buffy The Vampire Slayer, Battlestar Galactica, Supernatural, DC comics, The Wheel of Time, Lord of the Rings, even video games like Streetfighter and World of Warcraft have had tabletop roleplaying games published using their licensed material.
There are pros and cons, of course. While you have an immediate understanding of the setting and what the game is likely to be about, as well as the buzz of playing around in the setting of a favourite tv show, the group must figure out how to address problems like the presence of established characters. Typically this isn't an issue with villians - the players are usually heroes, so going up against Darth Vader or The Joker can be fun. But it can be a problem with heroic characters, who the players might expect to save them if they get in over their head.
Then there's the problem of choosing when in a particular setting's history to set your game. If you set it during the events, will the players' actions clash with the established plot? If you set it before, there's the danger of upsetting the starting status quo of the setting, or invalidating the players' efforts with the knowledge that the real heroes haven't known up yet. If you set it after, then there's the problem of figuring out what might happen next in the world, and the danger that further stories will contradict your own group's adventures.
My preferred method has always been to say that anything in a series or book that happened before the campaign is fact and has happened in our game world, but that everything else after that is fair game. Canon heroes can die, or fail in their task, their duties taken up by the players themselves. I firmly believe in making the players' characters the central heroes of the story, and the setting and metaplot must change to accommodate that.
Right now we're getting ready to start a new campaign using the Dresden Files roleplaying game. Starting in late 1999, before the first book in the series, this campaign will be a cross between Dresden Files, the A-Team, and Supernatural, with the players on the run from the Wardens of the White Council for a crime they didn't commit, travelling America helping those who no-one else will help, and trying to prove their own innocence.
Do any of you have any licensed settings you enjoy? Or do you prefer games with original settings, or coming up with your own from scratch?