GANGNEUNG, South Korea — Ever since the International Olympic Committee added curling to its official list of winter sports in time for the 1998 Winter Olympic Games, the sport has been a quadrennial source of curiosity — and something of an addictive force — for spectators across the globe.

The athletes — yes, they’re athletes and don’t you dare suggest otherwise — deliver polished granite orbs across a long sheet of ice. They use special brooms and wear special shoes and have their own special language, barking commands like “hurry hard!” Canadians, in particular, love this stuff.

Here in Pyeongchang, curling will clutter the calendar for 18 full days — longer than any other sport at the Games. Mixed doubles actually starts Thursday, the day before the opening ceremony. There will be no shortage of hurrying hard this month.

So as we dive back into the madness, a quick primer might be in order.

Without getting too technical, how do you play?

Let’s start with the men’s and women’s team events. There are four players on each team, who rotate jobs. But for each throw, one player delivers the rock — the aforementioned granite stone, which weighs between 38 and 42 pounds — two teammates sweep and the fourth person sets the target. The target is at the other end of the sheet. Known as the house, it’s a series of concentric circles that forms a sort of bull’s-eye.