I'm sure you've heard the old joke: I went to a fight and a hockey game broke out. The variation on it these days, in the part of LCT's basement floor whereWar Horse is assembling itself, might be: I went to a ball game and a rehearsal broke out. Such is the intensity with which the War Horse actors are indulging, at lunchtime, in a kind of playground activity that you might easily assume these 35 performers had been hired not primarily for their acting but for their competitive acumen. Specifically, for their ability to play a game known, in the vernacular, as "Ball-ie." 

The game, which the actors and a few other War Horse associates play at lunch hour with fervent kids-at-recess energy in the room next to the large rehearsal hall where more official War Horse activities take place, is a lot like the schoolyard favorite Four Square. Instead of a quartet, however, Ball-ie is played with nine people. They comprise a circle, with a tenth person in the center square, who serves the volleyball-size object into the group and who wishes devoutly to avoid elimination from a ball blown back by one of the surrounding pack. Play can get fierce: unlike Four Square, Ball-ie allows for smash tactics. 

Those without inter-murals experience aren't necessarily at a disadvantage, however. Hannah Sloat, one of the ensemble, told me: "People with an athletic background can bring those skills to bear, but a beginner can also do well." 

I must confess at this point that the game might also be spelled "Ball-y." Its orthography is almost as hazy as the question of who, exactly, introduced it to the company early in the rehearsal period. (The game was also played amongst the War Horse cast in London, with the imprimatur of Tom Morris, one of the production's directors.) Was it Toby Sedgwick, Director of Movement and Horse Sequences? Mervyn Millar, the Associate Puppetry Director? Who? 

I'm not about to settle the matter here and subject myself to all kinds of potential trouble. Millar told me: "The company here in New York are a pretty aggressive lot, so the game's a good way to burn off energy. I'm glad to see that Ball-ie is the game of choice right now for these actors. I expect that the crossword brigade" - he refers to the fact that, in the theatre, actors and directors of a certain age are forever pestering each other with questions like "Did you get 32 Down, the one about the Brest-Litovsk Treaty?" - "will supplant us at any minute." 

Millar, it must be inserted, has quite a reputation for his skill at Ball-ie, a reputation that, he says, "is not quite entirely deserved." (The key word in that sentence is "quite.") Zach Villa, one of the show's performers, who jokes that the War Horse company is going to introduce Ball-ie to the wider Broadway community, as a cold-weather complement to the industry's vaunted summer softball league, begs to differ. "One day Merv stayed in the center square for 20 turns in a row." But actors, too, excel at Ball-ie, some of them sufficiently so that their prowess has already inspired pugilistic pet names. The jarring body shots of Joby Earle have earned him The Assassin, and the Federerish serving hand of Prentice Onayemi has garnered The Silky Touch. 

And Millar? He is reverenced with: The Master. 

Brendan Lemon is the American theater critic for the Financial Times and the editor of lemonwade.com.