The Good Book tells us that marriage is to be entered into reverently and not to be taken lightly. But nobody said anything about being married by a justice dolled up as Elvis, the Godfather or Austin Powers. “Married in Vegas” (9 p.m., A&E) chronicles the oddly colorful characters who toil in the gambling mecca’s wedding industry.

Ron, one of the “stars” of “Vegas,” is a regular multitasker: He can double as both Elvis and Merlin. He also cleans out the bathrooms for his blushing brides and eager grooms.

Folks like Ron perform an average of 315 weddings per day, including well-thought-out “theme” ceremonies as well as sloppy ceremonies between impulsive brides and grooms, who may or may not remember that they’ve tied the knot. It’s a good thing that Reno, once known as America’s divorce capital, is located in the very same state.

Tonight’s other highlights

¢ “Average Joe: The Joes Strike Back” (7 p.m., NBC) offers the fourth helping of an idea that didn’t have two seasons in it.

¢ The National and American Leagues tangle in the 2005 All Star Game (7 p.m., Fox), live from Comerica Park, home of the Detroit Tigers. What on earth is a “comerica”?

¢ Ivy League secrets on “Gilmore Girls” (7 p.m., WB).

¢ Ace reporter Julie Chen is host on “Big Brother 6” (8 p.m., CBS).

¢ “Wide Angle” (8 p.m., PBS) enters a new season with “Beslan: Siege of School No. 1,” an account a terrorist attack on a Russian grammar school that left hundreds dead.

¢ Performers audition on “Rock Star: INXS” (9 p.m., CBS).

¢ Kyle MacLachlan guest stars on “Law & Order: Special Victims Unit” (9 p.m., NBC).

¢ A snake proves less than charming on “Empire” (9 p.m., ABC).

Late night

Jennifer Lopez and Snoop Dogg appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno is host to Dakota Fanning and Rascal Flatts on “The Tonight Show” (10:35 p.m., NBC) … All American Rejects appear on “Jimmy Kimmel Live” (11:05 p.m., ABC).

Scarlett Johansson, Jeffrey Tambor and The Decemberists are booked on “Late Night with Conan O’Brien” (11:35 p.m., NBC) … Craig Ferguson is host to Dave Navarro, Marisa Acocella Marchetto and Ron Pearson on “The Late, Late Show” (11:37 p.m., CBS).