[aephi alum]

I've always had a fondness for board and card games, so I'd go with that.

I tend to go in for Euro games like Settlers of Catan and Carcassonne. For a formal recruitment party, though, I'd go with games that most people know, so you don't end up spending the entire party teaching a new game to the PNMs.

The chapter would have several copies of various games available, along with a bunch of decks of cards. PNMs would be picked up in pairs or triplets (2 PNMs + 2 sisters, or 3 PNMs + 3 sisters). The group of 4 or 6 would then go over and pick out a game, find a spot around a table or on the floor, and play. When the game is over, if there's still time left in the party, the group can chat. (You'd probably want to choose games that would leave time for chit chat - e.g. if the party is 45 minutes long, you would want games that typically run 30 minutes or so.)

You can tell a lot about a person by how they play a game - uber-competitive, sore loser, "I usually like to use the blue pawns, but that's ok if you want to play blue, I'll use red", etc.