A discussion with a housemate yesterday made me realize just how easy it would be to run an Avatar game using the FATE Core System. I figure I'd share that today and maybe provide a starting off point for anyone who was looking to run a home brew game in that universe. Who knows, maybe I'll get to run my own game there at some point in time. So here is how it works.
Stealing Refresh From Dresden Files
The first thing we need for character creation is to steal Refresh from the Dresden Files game. Ideally I think all PCs would start with 7 refresh (maybe 8, but I think 7 works.) Refresh would determine how many FATE points a PC starts each session with like normal, but could also be spent (like in Dresden Files) for abilities and stunts. For Avatar you would also be able to spend Refresh for signature gear.
So how much would things cost? Well, the ability to be a Bender would be 4 points and you would have to choose your element you could bend. If you have Avatar as a high concept (or some other concept worked out with the GM potentially) you can add additional elements on board for 2 refresh. Each element would also have an "upgrade" that could be bought for 2 points (i.e. lightning for Fire benders, Metal for earth benders, and Blood for water benders.)
Stunts would be 1 refresh per stunt as normal.
Gear would be the hard part. The cost would have to depend on the item itself. Something like Ang's glider staff might cost 2 points while Sokka's boomerang could be 1 or 2 points depending on how useful you think it is.
A standard fantasy skill set would easily work for the Avatar universe. Most people would use Fists for fighting, but some would also use Weapons. Guns doesn't seem like something that is needed. There would however need to be a skill for Bending.
Bending would need special rules for the Avatar. Namely that the skill could function at -2 to -4 ranks for elements that the Avatar hasn't bought yet as mastered. The Avatar also shouldn't be able to bend their counter element (more on this later) until it has been bought/mastered as that seems to be a major story point in both series we've seen so far.
Elements and Counter Elements
The Avatar world seems to have people paired up with Elements to determine their emotions and how they confront people. This seems to be related to the nation they're from, but Korra also shows that the element someone identifies with isn't necessarily related to where they were born.
What do I mean by this? Well, Ang was clearly Air and thus had the most problem with learning Earth. This makes sense because Air and Earth are opposites. Air wants to find a way around, Earth wants the direct confrontation and Ang had problems with learning that. On the other hand, Korra was water so it would make sense that Fire would be her opposite. Except that Korra has the most problems with Air. Her direct approach mentality (Earth in nature it seems) makes Air hard for her to learn, which is the premise of the first season of Korra's run.
Other people follow these guidelines as well. Kai Lee is an Air type person while Zuko and Azula are clearly Fire. Katara is a softer side of Water while Sokka is still Water but in a more martial way.
Elements are most important for Benders, but other people should make note of it as well. After all, it feeds into a lot of the world.
What About Spirit Bending?
Spirit Bending is a strange beast. It hasn't been fully explained in the world that I've seen, and would likely need special rules. Luckily though, it also seems incredibly rare.
Theme and Feel
Lastly, beyond mechanics, what about theme and feel? Avatar, to me, seems to be about growing up. It features the clash of the expectations on teenagers and their struggle to grow into the world. Whether this is Zuko trying to live up to the family name and make his father proud, Ang trying to make up for his moment of fear a long time ago, or Korra trying to balance what it means to be the Avatar and a person who wants to experience and enjoy their life because the world doesn't necessarily need an Avatar at the moment.
Beyond that there is also the clash of Idealism vs the way things are, with the idealism being the side the main characters are on and fighting for. In both the Ang series and the Korra series there were clear feelins of "this is the way should work" based on the ideals of the characters, and a simple world view that is almost child like (again, the feature on growing up.) Only, in Avatar, it is possible for the world to be made that way. It just needs people to stand up and fight for it.
Sounds like the perfect job for a bunch of PCs, huh?