If you don't want to be sawed in half, you might want to hide under your chair. That's because David Shiner and Bill Irwin, the two Tony-Award-winning clowns behind Old Hats, playing through April 14 at Off Broadway's Pershing Square Signature Theatre, would very much like to pull you up onto the stage so that you can join their magic act. Later, they might want you to pretend you're in an old-fashioned Western, slamming down drinks and shooting your way through a duel, right in front of the whole audience. So if you aren't a big fan of audience participation, you've got two options: Stay home, or throw someone else into the aisle before you.
If you're brave enough to risk it, though, these guys will make it worth any small-grade humiliations you might suffer. Ever since Shiner and Irwin made their breakthrough with 1993's Full Moon, critics have compared them to other outstanding duos Laurel and Hardy, bourbon and soda, bacon and eggs. Both men share a love of old-timey comedy: Irwin attended the Ringling Brothers and Barnum & Bailey Circus before pursuing acting, and Shiner worked as a street performer in Paris before joining Cirque du Soleil. And their latest series of comedy shorts feels just as classic, drawing on silent-film-era slapstick, sad-hobo mime acts, and Cole Porter-style ballads (played live by the vaudeville-inspired singer-songwriter Nellie McKay, who also acts a bit in the show). There is only the occasional nod to 2013. In ''Mr. Business,'' Irwin takes a photo of himself with his iPad, only to see that self-portrait take on a life of its own. But sketches like ''The Debate,'' which finds Irwin and Shiner playing rival politicians, manage to feel totally of-the-moment even though the gags are old. The two men stand behind the podium, arguing loudly, exposing each other's dirty secrets, and fighting to see who can kiss the most babies, while the audience watches their approval ratings rise and fall. Oh, and they somehow manage to make this very funny without saying a word. It's a joke that would've worked as well in Charlie Chaplin's era as it does in ours.
Irwin and Shiner can get you to laugh at other people's shame very easily. The funniest moments in the production when a drunk clown cries on a park bench in ''The Hobo,'' or when a magician's assistant (played by Irwin in drag) gets more and more enraged over her boss' flirtations with the crowd in ''A Magic Act'' are also the most uncomfortable for its characters. And when Shiner invites members of the crowd on stage to play those characters in ''Cowboy Cinema,'' a short that casts theatergoers as stars in a shoot-'em-up movie, most of the best comedy comes from watching just how far these people will go to ham it up for the spotlight. But there's real compassion here, too: not long after ''The Hobo'' invites you to laugh at all the clown's sobbing, it ends with a scene that's genuinely sad.
The show is called Old Hats for a reason: A few of the sketches recall the duo's earlier work. Anyone who remembers the two grumpy men who waited for a train in Full Moon will recognize the characters in ''The Encounter,'' which features a similar scene. But the callback works, because the two top-hatted, baggy-trousered men at the station are older now, and they're more curmudgeonly, too. The scene is a good reminder that 20 years have passed since Fool Moon. Same old hats, same old tricks but they still work. B+