When Lillian Hellman’s “The Little Foxes” plays on Broadway, Laura Linney will crawl under the thick skin of Regina, the furious Southern wife cut out from her family inheritance in 1900, and Cynthia Nixon will play her delicate, alcoholic sister-in-law Birdie. Or will it be the other way around?

For the Manhattan Theatre Club’s revival of Hellman’s 1939 drama, the actresses are switching roles, often after three performances, sometimes between matinee and evening. (To see a color-coded calendar of who’s when, visit littlefoxesbroadway.com.)

Star-driven alternations are not unknown, of course, but far more frequent in London than on Broadway. In the 19th century and into the ‘50s, or until white actors in blackface became a disgrace, it was not unusual to find actors switching between Othello and Iago. Laurence Olivier and John Gielgud shared the unequal demands of Romeo and Mercutio in 1935. In 2011, Benedict Cumberbatch and Jonny Lee Miller each got to know how it felt to be Frankenstein and his Creature.

And just last fall, Juliet Stevenson and Lia Williams each played each queen in Friedrich Schiller’s “Mary Stuart.” As if that were not enough adrenaline, the women flipped a coin before each performance to decide which one, as described in the Financial Times, would wear the crown and which would lose her head. Vehement that this was no gimmick, Stevenson said the toss represented “the terrifying randomness in life — and the delusion that we have about control.”

Closer to home, the highest-profile Broadway switch was in 2000, when Philip Seymour Hoffman and John C. Reilly played both the contrasting brothers in Sam Shepard’s “True West.” Since the screwball tragicomedy means to expose man’s dual identity, the double casting added a dimension to theatergoers willing to go — and to pay — twice.

Nixon, taking a break from preparing for previews of director Daniel Sullivan’s productions, finds strength in the emotional and technical challenges in the switch. “I don’t know how it would be to share roles with any other actor,” she said in an email. “But sharing with Laura is pure delight. I steal what I can from her, we bend one another’s ear about character things that are confusing to us, and we are always each other’s biggest cheerleaders. It’s also funny to me that our ‘experiment in sharing’ is happening inside of a play which is all about the bleakness of a family whose members are unable to share.”

Linney describes the experience thus far as wonderful. “Everyone has been so game (and patient) to see what happens,” noting that both actresses feel fortunate to have been given this opportunity. “Women rarely get to do this,” says Linney. “What I have loved seeing is how it affects the play as a whole, and how the rest of our cast reacts and shifts depending which Regina/Birdie they are looking at. And of course, if one embarks on such a journey you better have someone as rich in talent and as giving in collaboration as Cynthia Nixon. Otherwise, it could be a disaster.”

Some amusing back stories about "True West"  are included in Peter Shelley’s biography “Philip Seymour Hoffman: The Life and Work.” The actors flipped a coin to decide the opening night casting. Hoffman said the blocking was the same but interpretations were not, and they got laughs in different places. He also said the early rehearsals were an ego challenge because Reilly was figuring out the play faster.

In order to avoid competition, they wanted the Tonys to consider both performances as a single entity. The Tony Administration refused, but both were nominated for best actor. (They lost to Stephen Dillane in “The Real Thing.”) Since Regina is more of a principal role (created by Tallulah Bankhead) while Birdie is more of a supporting character, we don’t expect any such dust-up this season.

As I’m sure the stars of “The Little Foxes” would say about now, switching roles means double the work — stress both for the memory and the psyche. Several years before Ian McKellen and Patrick Stewart brought director Sean Mathias’ marvelous production of “Waiting for Godot” to Broadway in 2013, they considered switching parts during the London run. According to Playbill, Stewart thought it was a “charming idea.” McKellen said it was a “stupid idea,” and Stewart compromised that it was a “stupid, charming idea.”

It never happened.