In a building that once housed a discount women’s clothing store and was the headquarters for the Zionist Organization of America, 12-year-old Carter Radmiller stood in a dark room, blowing away zombies.

His eyes were pressed snugly against a virtual reality headset, and both of his hands gripped plastic controllers, while his avatar stood on a rocky outcropping, firing bullets and hurling grenades, dismembering the hordes of undead mutants that lumbered toward him from every direction.

A few feet away, his mother, Eileen Radmiller, watched Carter’s progress on an enormous monitor. The two of them were in town from San Francisco for vacation. It was frigid outside, and they had spent the whole day at VR World on East 34th Street, which bills itself as “the largest virtual reality experience center located in North America and the Western Hemisphere.”

Ms. Radmiller said this was their first encounter with virtual reality, and that they had played most of the dozens of games VR World has to offer. “It’s amazing how quickly he picks it up,” she said.