A cannabis dispensary might seem like an unlikely place to play mahjong, the Chinese tile game typically associated with older Asian and Jewish adults, but that’s where Leah Flacco showed up on a recent Wednesday evening in Manhattan.

The game has grown in popularity with younger generations, so at a table inside Alta Dispensary in NoLIta, Ms. Flacco, 36, shuffled and matched groups of tiles among friends and strangers. The event was one of a growing number taking place at New York’s cannabis dispensaries, where retailers have been making space for people to socialize.

“We want more dispensaries to do these sorts of things,” Ms. Flacco, who works in financial technology, said. “It’s hard to make friends in this city.”

From intimate classes to block parties, hosting events has given dispensaries in New York a way around rules limiting their ability to market their businesses. As many Americans choose to drink less alcohol and seek connection offline, the activities allow the sellers to offer places where people can gather. Dispensary owners also hope that some of the visitors will become customers and that the events will help their businesses gain acceptance among neighbors who might still hold negative views of cannabis.

Meredith Nydam, 37, said she had invited her friends, including Ms. Flacco, to mahjong night because she wanted to do something other than a happy hour. “I don’t need to go to a bar,” Ms. Nydam said. “I can come here.”