In the 14 years since it opened, Eleven Madison Park has slowly become one of the most elegant and esteemed restaurants in New York City. With its high ceilings and hushed grandeur, it feels like a sanctuary. Its sophisticated cooking and polished service have earned it three stars from Michelin, four from The New York Times and a recent jump into the top 10 of a much-watched list of the world’s best restaurants.

And now, at the height of their game, the owners are planning to throw out the formula.

Not long after Labor Day, this understated refuge on Madison Avenue will start treating diners to flashes of Broadway dazzle: card tricks, a glass dome full of smoke, a blast of sea mist from a tabletop clambake and a cheese course that emerges from a picnic basket placed on the table. It’s all part of a $195-a-head menu — and a risky move to convert the Eleven Madison Park experience into an extravagant, participatory, close-to-four-hour ode to the romance and history of New York.

Will the transformation delight customers, or alienate them by seeming gimmicky?

For Daniel Humm, the executive chef, and Will Guidara, his business partner and the general manager, both of whom are still in their 30s, the gamble represents a once-in-a-generation chance to redefine what going to a four-star restaurant is all about. As Mr. Guidara put it, “How many times in your life do you have an opportunity to leave your own legacy?”

They may have no choice if they want to continue ascending toward the world’s culinary peak. Restaurants in the very top echelon these days — Noma in Copenhagen, Alinea in Chicago, Mugaritz and Arzak in Spain — sell cooking as a sort of abstract art or experimental storytelling. Wild, thought-provoking leaps are required for greatness, but they can backfire. And when they do, results can be ruinous: consider Romera New York, which closed in March, only half a year old, after its odd gastronomic experiments drew poor reviews and ridicule.