To celebrate the 20th anniversary of the “Madden NFL” franchise, publisher Electronic Arts is throwing a party for the game at the Rose Bowl in Pasadena, Calif.

That’s where the game’s namesake, John Madden, coached the Oakland Raiders to his only Super Bowl win, a 32-14 drubbing of the Minnesota Vikings in 1977. And that’s where, on Aug. 11, “Madden NFL 09″ will have its coming-out blow out a day before the game’s official release.

EA’s calling the day-long get-together “Maddenpalooza,” featuring food, live bands that include Busta Rhymes and Good Charlotte, as well as 300 gaming kiosks for attendees to try finding the reported 85 new features and enhancements in this year’s edition of the game. (Among them is “adaptive” play — in which the game continuously assesses a person’s skills and automatically adjusts the gameplay as the player improves.)

Also, Wal-Mart will have tents set up in the Rose Bowl to sell the first copies at 11 p.m. St. Louis time.

Game Guy’s not sure what the attendance limit is — the Rose Bowl seats upwards of 90,000 — but admission is said to be free and open to everyone. Los Angeles-based radio station KIIS will give out a bunch of the tickets, but Madden fans can also can get in on the fun if they line up outside the stadium early enough: Tickets available on the day of the event will be distributed on a first-come, first-served basis, EA says.

So, Madden fans, if you’re not in LA now, gas up the car and head thataway now. And pack a sleeping bag and a lawn chair. No sense not being comfortable while camping in the ticket line.