A coalition of American Jewish groups are placing their bets on Las Vegas, a destination they hope will simultaneously lure back young adults and groom their next generation of leaders.

More than 1,200 22- to 45-year-olds have signed up for TribeFest 2011, a combination mixer and symposium at the Mandalay Bay Resort and Casino. The March 6-8 event, sponsored by the Jewish Federations of North America, aims to engage Jewish young adults culturally and spiritually.

“It’s about widening the tent,” explained Beth Mann, the Jewish Federations’ associate vice president. “There will be people from across the religious spectrum. We have Chabad, we have punk Jews, we have women rabbis, we have people who wouldn’t be caught dead with women rabbis.”

The event comes at a transitional time for American Judaism, which is grappling with a membership crisis in non-Orthodox congregations and concerns about the high cost of synagogue membership and Jewish day school tuition.

Contributing factors, which are hotly debated among Jews, include the decline of anti-Semitism and accompanying rise of intermarriage, lower birth rates among liberal Jews, the Israeli-Palestinian conflict, the economic downturn and shifting cultural priorities.

TribeFest is taking an “all of the above” approach, with discussion topics including U.S.-Israel policies, interfaith relationships, homosexuality, female leadership, social media and what it means to be Jewish today.

Two of Judaism’s great success stories of the past decade -- the ultra-Orthodox Chabad movement, and Birthright Israel, the nondenominational program that offers free trips to Israel for young adults -- are among the participating groups.

“This is a very different kind of event than what we’ve done in the past, which were more aimed at people who are already active in the Jewish community,” said Joe Berkofsky, a spokesman for the Jewish Federations. “For some, this will be their first Jewish experience of any kind.”

Speakers will represent the worlds of religion, culture, sports, politics and business, including actress Mayim Bialik (TV’s “Blossom”) and author Ben Mezrich, whose book, “The Accidental Billionaires” was adapted into the Oscar-nominated film, “The Social Network.”

Organizers are gambling that when their Jews wander back out of the Nevada desert after the three-day event, they’ll be more inspired to forge stronger connections to Judaism -- whether through a congregation, a cultural organization, or simply by having made new Jewish friends.

To put it another way: this time, they hope, what happens in Vegas won’t stay in Vegas.

“Instead of us telling them what we think Jewish communities should be for them,” Mann said, “we invite them to help define how to create Jewish communal opportunities for each other.”