Elisabeth Vincentelli

Elisabeth Vincentelli

Theater

Ian McKellen dominates aside best bud Patrick Stewart

Right now Broadway exists in an alternate reality where bleak existentialism is trending.

But there’s a simple explanation for Pinter’s “No Man’s Land” and Beckett’s “Waiting for Godot” thriving amid a sea of light musical fare: They both star Ian McKellen and Patrick Stewart — better known as Gandalf and Captain Jean-Luc Picard, respectively.

When you’ve done Middle Earth and “Star Trek,” you can get away with anything.

Unlike many marquee names who wash up on the Great White Way, these two know their way around a stage. They have what seems like 328 years of combined experience, with dozens of highfalutin’ notches in their actorly belts. These guys’ screen credits may be luring crowds, but it’s their craft that earns the applause.

Like Mark Rylance alternating between “Richard III” and “Twelfth Night,” McKellen and Stewart do their shows in rep, and both are directed by Sean Mathias. If you have to pick one, “No Man’s Land” is the way to go.

That 1975 play helped popularize the term “Pinteresque” as shorthand for something that’s enigmatic, dry, vaguely threatening and vaguely funny.

Spooner (McKellen) is a down-on-his-luck poet invited to the fancy home of Hirst (Stewart), a rich literary figure. Hirst is helped on by a couple of manservants played by local stalwarts Shuler Hensley and Billy Crudup, ably representing the American acting corps.

Maybe Spooner and Hirst know each other, maybe they don’t. Maybe the things they talk about happened, and maybe they didn’t. Even an innocuous line like “Let us change the subject. For the last time” leads to mind games.

It’s all very inscrutable and cool, but the show’s mysteriously compelling. This has a lot to do with the easy rapport of the leads, who are besties in real life — McKellen even became a Universal Life Church minister to officiate at Stewart’s wedding.

Still, this doesn’t prevent McKellen from wiping the floor with him. At 74, he’s lighter on his feet than men a third his age, with a highly entertaining mix of looseness and precision, and a stunningly mobile face.

Though the two main roles in 1953’s “Godot” are equal, McKellen comes out on top again as Estragon to Stewart’s Vladimir. The pair are bedraggled vaudevillian tramps in bowler hats, endlessly hankering for a visit from the mysterious visitor of the title.

For some reason, this “Godot” has been set in what looks like a crumbling theater instead of the usual desolate landscape. But the real reason the show’s less efficient than the other one is the imbalance between the leads — once again, McKellen’s dominance turns Stewart into a straight man.

The supporting cast is just as lopsided: Hensley’s bellowing Pozzo is one note, but Crudup is touching as Pozzo’s slave, Lucky.

Yet every time you start thinking you’re watching two homeless men argue, the ever-expressive McKellen pulls out another trick: Just look at the way he gnaws on a carrot, or his desperate soft-shoe shuffle. Who wouldn’t want the privilege of watching him in action?