John Legend is performing at Haze nightclub at Aria, Ne-Yo is welcoming the new year at Pure nightclub at Caesars Palace and Maroon 5 is playing at Mandalay Bay. Pop star Bruno Mars is christening the Cosmopolitan's new Chelsea Ballroom. The show will be broadcast live on the casino's 65-foot (20-meter) marquee to ice skaters at a rooftop rink and partyers on the Strip below.
Other casinos are touting pricey nightclub bashes with $3,000 bottle service and open bars hosted by reality-TV and music celebrities, including the original celebutante, Paris Hilton.
More than 330,000 tourists are expected to count down the end of the year as law enforcement officers keep the peace and casino bosses watch profits roll in.
With New Year's Eve falling on a Tuesday, many casinos offered up special ''New Year's Eve Eve'' events on Monday and advertised the two days before that as the biggest weekend of the year.
On Tuesday, casinos will start the revelry as early as possible. At Mandalay Bay, the Minus5 Ice Bar will start handing out free champagne for hourly toasts at 11 a.m.
The winter months are Las Vegas' slowest, which means casino executives are especially eager to lure as many patrons as possible on New Year's Eve, a holiday seemingly custom-made to align with Sin City's boozy, bad-judgment ethos.
''The Las Vegas brand is about freedom, and that means different things to different people. Adult freedom is on display everywhere on New Year's Eve,'' Las Vegas Convention and Visitors Authority spokeswoman Heidi Hayes said.
Hotel occupancy is approaching 100 percent for Tuesday, according to Hayes, who emphasized that beds remain available for anyone contemplating a last-minute trip. Rooms are going for about three times the normal price.
Those looking for a less costly experience than the Strip's over-the-top offerings can head 15 minutes north to downtown Las Vegas, where the Fremont Street Experience pedestrian mall is hosting a block party with acts including Blues Traveler and Papa Roach.
Virtual fireworks will light up the mall's blocks-long metal canopy, which boasts the world's largest video screen.
Those hoping to avoid drunken revelry completely can see Kristin Chenoweth perform at the elegant Smith Center in a hidden corner of downtown.
Las Vegas' New Year's Eve festivities, dubbed ''America's Party,'' have doubled in size since 1990. Still, the party is far from the world's largest. The ball drop at New York City's Times Square draws more than 1 million spectators, and some 2 million people flock to the shores of Copacabana beach in Rio de Janeiro for music and fireworks.
Spectators in Sin City will be treated to more than eight minutes of coordinated pyrotechnics. The fireworks will be shot from the rooftops of seven hotel-casinos, from the MGM Grand toward the south end of the Strip to the Stratosphere in the north.
Police plan to shut down Strip traffic six hours before midnight so that revelers can spill into the 4-mile (6.4-kilometer) stretch of road normally packed with cars.
The city's 2,700 metro police officers will be visible on the Strip and will also blend into the crowd. About 300 Nevada National Guard troops will take up stations around town, on the lookout for possible terrorist threats. Around 2 a.m., street sweepers will move in and collect about 50 cubic yards (38 cubic meters) of trash.
Always eager to attend to revelers' every need, a host of casinos and restaurants are offering hangover brunches for tourists on Wednesday morning.