In my spare time (of which there is not enough), I have many recreational interests, but the one I spend by far the most time on is solving and constructing puzzles.
My first exposure to logic puzzles was the "who owns the zebra"-style grid puzzles your elementary school teacher uses to keep you busy, and while I enjoy those (if they're interesting enough), I spend a lot more time on abstract logic puzzles, especially when I can do them in competitive situations. (Abstract logic puzzles are like sudoku in that they usually involve filling in cells with numbers, symbols, lines, or colors, based on some constraints. Once you know the constraints, the puzzles are language-neutral, so the solver and constructor don't have to share a language.
On a regular basis, I solve puzzles under the pseudonym Spelvin on Logic Masters India and Croco-Puzzle. The latter of which is a German site, so it takes some getting used to if you don't speak German. Chrome translates it pretty well, though. I've also recently been solving puzzles on David Millar's site, The Griddle. I would describe his work as inconsistent but often fun (which probably is a good description of my own puzzle construction). I used to solve on Nikoli's website, but I found it was taking too large a chunk out of my free time. (And you can probably tell from the length of this page that that's an issue.
Every year I compete in the US Puzzle Championship, which determines the US team for the World Puzzle Championship. Most years I perform well enough to be named an alternate (sometimes ahead of people who make the team anyway due to grandfathering rules), but I've never been on the official team. I was part of the only B-team the US has ever sent to the WPC (Eger, Hungary in 2005), and we did very well, although our results were officially unofficial.
I'm also very fond of word puzzles and wordplay in general. I am a member, and used to be Secretary for, the National Puzzlers' League, the world's oldest puzzling organization. The NPL newsletter includes member-submitted puzzles in not my favorite types, though the cryptic crosswords are excellent. The real draw, however, is their yearly convention, where I get to see tons of nerdy friends and solve puzzles and play games. The name "Spelvin" I use on the sites above is my "nom de plume" in the NPL and comes from the traditional actor's pseudonym, George Spelvin.
I haven't been active recently, but I used to regularly attend the American Crossword Puzzle Tournament (if you've seen the film Wordplay, it's that tournament, and if you're eagle-eyed you might see me a few times). In my most recent appearance, I came in 18th, finishing second in the B division behind Dan Feyer, who has since won the entire tournament thrice so what can you do? I've also won the Westchester Crossword Tournament (a much smaller event) and the community division of the Brown Crossword Tournament. Most recently I finished fifth at Lollapuzzoola 2012 in Manhattan.
I don't write many traditional crosswords, but I write one or two cryptic crosswords a year. These are crosswords with "cryptic clues," which are much more prevalent in the UK and give the solver both a definition of the answer and a wordplay indicator mashed up into one clue. If you are intrigued by the idea that "Fragile items he will start to stow after safecrackers leave club" leads to the answer EGGSHELLS, there's a tutorial here.
At some point I'll post some of the variety cryptics I've written although many of them are specifically themed to the locations of NPL conventions. If you're just learning cryptics, there are a lot of accessible examples at Kegler's Kryptics. If you're more seasoned, the NPL has an excellent collection of cryptics downloadable for free, which includes my first bookstore-published puzzle. (The book's out of print now.)
When it comes to puzzles, my biggest passion by far is puzzlehunts. Mostly descended from a combination of the MIT Mystery Hunt and Stanford's drive-around event The Game, these events involve solving a collection of puzzles of highly variant types, the answers to which somehow combine to form metapuzzles which advance you farther toward a certain goal. The MIT Hunt is a "hunt" for a coin, but in many puzzlehunts, the ultimate goal is simply a final solution, and the nomenclature is mostly inherited from other events.
A running gag about these events that the puzzles frequently lack instructions, so in addition to solving, you need to figure out how to solve. Some people find this annoying, but I love it, as it requires a certain lateral thinking that I've become quite good at. I also like the fact that, as opposed to a crossword or sudoku competition where you are required to fill in every square, the goal of a puzzlehunt puzzle is to get to a short answer, and often one can bypass part of the solving via creative thinking (or "wheel-of-fortuning" missing letters in the final clue). Thus, analyzing the big picture and determining the most efficient way to get from Point A to Point B becomes a very useful skill.
Some of the puzzlehunts for which I have written puzzles include:
- The granddaddy of them all, the MIT Mystery Hunt (2000, 2002, 2005, 2007, 2009)
- The NPL Convention Saturday night extravaganza (2005 and 2010)
- The Gen Con Puzzlehunt (at Gen Con, a major gaming convention)
- A semi-controversial alternate-reality game called The Citizens of Virtue
- BAPHL 6, a rock-band-themed puzzle hunt that ran in the Boston area in September 2012
I highly recommend the puzzlehunts written by Foggy Brume in P&A Magazine, a bimonthy e-zine of puzzles which costs a measly $5 an issue, and by Mark Halpin, who writes a hunt every year for Labor Day. Mark's puzzles are free, but his work is well worth throwing something in the tip jar.
Finally, each year that I'm not on a team writing the MIT Hunt, I traditionally prepare a warmup hunt for my team in anticipation of trying to win the Hunt. (These mini-hunts are later released to the Internet at large.) You can find eight(!) of them here. The first two are kind of light; 2006 is when I started writing more substantive puzzles for these.