I've played it. However, it doesn't really work anymore unless you sit down with the players ahead of time and force them to watch a few episodes of Dallas - and that is a torture beyond belief.
However, it makes it WAY more surreal to watch a game being played now if you do have that background, because the characters are so all over the place. Imagine watching an episode of Numb3rs where Charlie Eppes is the take-charge kind of guy and Don ends up in the back seat, acting as a liaison man and interface between the uber-geek in charge (Charlie) and the FBI hardass Megan Reeves. (Of course, all that means nothing if you don't watch Numb3rs).
Anyways, the game play is pretty simple. Characters try to Affect each other using Persuade, Coerce, Seduce and Investigate, and if an Affect attempt succeeds, the target must give up something (control, information, power, etc).
Each character has stats for affecting and defending using each of these abilities as well as a Power & Luck stat. Major characters can even gain control of minor characters through the Affecting rules, allowing them to get more done, or to do things without being quite as open about it. Unlike most games, there are distinct "winning" rules, as the characters are often at direct odds with each other through a plotline, and who comes out on top will affect future stories.
The game has three full "scripts" to play through. Each major character has a set of victory conditions to "win" the script (basically what they have to control by the end of the game). This allows for the power disparity to work well, as J.R. has significantly better stats than most of the other characters, but usually has such high power needs that it can be difficult for him to succeed at his tasks - however it remains possible that one or more other characters can succeed at their tasks while JR succeeds at his. Best of all, like in the TV show, the characters are often fighting for control of the same resources, at cross purposes, in order to "help" the same end cause. J.R. is speculating, while Jock is protecting - if either one wins then Ewing Petroleum will win... but they are directly fighting one another to help the company out in their own way.
It's a very social RPG - there are no rules for violent confrontation, as close as it gets is coersion which is handled much like you would expect in an 80's TV show - when it really comes down to pushing and shoving, you have your thugs do it.