AirPlay and CBS teamed to create a mobile game, challenging viewers of the Big Brother television show to join the competition via their handset.

Starting July 13, fans can play "Big Brother: Live TV Challenge" to become the first interactive champion of the show and be eligible to win a trip to the live season finale in Los Angeles.

"Big Brother has a large fan base and these people want a part of the action," said Chris Bull, vice president of marketing for AirPlay, San Francisco. "We believe there is a substantial opportunity with engaging them with other fans and with the show."

To download the game, viewers must text the keyword BB10 to short code PLAYTV. In return they receive a link to download the game.

Consumers who download the game are automatically entered into a sweepstakes. The winner is announced on the Big Brother Web site and wins a trip for 2 the Los Angeles for the show's season finale.

"The game provides fans with a social and competitive experience," Mr. Bull said. "It enhances viewers' involvement in the show."

Players interact with other fans by chatting and competing against one another through predictions, "Pop Polls," trivia and memory of past show events.

Viewers compete and play in real time against a community of fans via their mobile devices or the Web for the definitive television viewing experience.

The game is available on wireless carriers Verizon Wireless, AT&T, Sprint and Alltel. Carriers charge $2.99 to download the game.

Season ten of Big Brother will follow a group of strangers living together in a house outfitted with dozens of cameras and microphones recording their every move 24 hours a day, seven days a week.

One by one, the house guests will vote each other out of the house until at the end of three months, the last remaining house guest will win the grand prize.

The Big Brother game is not ad-supported.

"The current state of mobile gaming is stagnant," Mr. Bull said. "There's a lot of the same stuff delivered and today's top five titles are the same as last year's.

"AirPlay is trying to lead a dynamic change in how people use their phones," he said.