What: The annual gathering of the National Puzzlers’ League somewhere in North America in July. This year it is in Seattle, starting tomorrow. Details of the convention can be found here.

Why: The National Puzzlers’ League is the world’s oldest puzzle organization, founded in 1883. At the time, its members gathered in small groups in hotels to solve word puzzles and trade amusing stories. 127 years and 170 conventions later, that’s exactly what still happens. Master of ceremonies Will Shortz, he of the New York Times crossword and National Public Radio, leads the gathering in a dozen or more official games prepared by members, usually for all the attendees at once. The unofficial games, though, are what many most look forward to. There’s walkaround puzzlehunts, homemade Jeopardy! games, insane charades, and puzzling till all hours. At one convention in Cambridge, members noticed that the courtyard was made of large square shapes. So they gave 16 attendees large signs with letters on them, had them run around the squares, and turn their signs toward the heavens. Why, you ask? Well, imagine you are on the 14th floor of the hotel looking out a window. That’s the biggest Boggle game you’re ever gonna play. Only at the NPL con could that happen.

Impact: The NPL is where all the best puzzlers end up. It’s hard to call a group with a public website and a public convention a “secret society,” but it’s possible that if you walked into its convention you might think you’d joined one. Everyone has a nickname, called a “nom,” which helps obscure the fact that some of them are famous (Will Shortz’s is “WILLz,” or “Will short z”) and some are not. The noms make everyone equal; if you walk in the door, you’ll be welcomed and put to work solving something bizarre. It is where many of us made the best friends we’ve ever had.

Personal Connection: When I started creating puzzles for a living, my editors Henry Rathvon, Emily Cox, Mike Shenk, and Will all lobbied me to join the NPL. Said it would be the best decision I ever made. I catch on quickly, so a decade later, I took the plunge under the nom Slik (letters read left to right in my last name). Seven years later, I went to a convention in Montreal, and got a lot of the “Oh my gosh you’re Mike Selinker I’ve wanted to meet you for years I’m so glad you joined here solve this you have forty-five seconds” kind of comments. I haven’t missed any of the 16 cons since. If you go to the one in downtown Seattle at the Red Lion starting tomorrow, there’s a good chance your Julys will have a permanent itinerary item. Come on along, and bring your brain. It’ll never be the same afterward.

Other Contenders: I can hardly be fair about this, since I work for or at all these shows. But I will strongly recommend PAX in Seattle and Boston, Gen Con in Indianapolis, and Origins in Columbus. I’ve been to something like 48 of those, and had a great time every one. There are lots of other smaller conventions, so seek one out and join the fun.