This is a simultaneous, two-player version of Hangman (or Wheel of Fortune). I tried this with my friend last week and it was fun! Here's how it works.
Agree on a category; say, movie title. Each player writes down a blank puzzle
(like "_ _ _ [space] _ _ _ _ _ _ _" for "The Goonies"). It's
best if the two puzzles are about the same length.
Now the guessing begins. I guess a letter. The other person has to fill in all occurrences of that letter in their puzzle. But here's the catch: I ALSO have to write in all occurrences of that letter in my puzzle!
Then the opponent guesses a letter, and again, we BOTH have to write in all the occurrences of the letter in our puzzles.
So the goal is to guess letters that aren't in your own puzzle, but that you think will be in the opponent's puzzle.
Anyone can shout out a guess at the opponent's answer at any time. This isn't like normal hangman where you can take 3 hours thinking about the answer after your seventh miss to "avoid getting hanged." Here, every second that ticks by can be your death. You never know how close your opponent is to figuring out your puzzle.
(But: if you guess and you're wrong, then the penalty is, the opponent gets a free turn during which you MUST KEEP SILENT even if you then realize the answer). So then your opponent does, essentially, get unlimited thinking time.
There's a lot of interesting subtlety in this game; for example, in trying to read the opponent's guesses. For example, if my opponent has guessed I, O, and U, it becomes conspicuous that she left out A and E. Why? Because *her* word is probably full of A's and E's. But does that mean I should guess A and E now? Possibly not; maybe it's not worth wasting a turn: maybe just knowing those letters are in there *somewhere* is enough to help me solve her puzzle.
Sometimes guessing a letter that you also have could be a good choice. For example, if one of your words is _ _ _, chances are the opponent will figure out it's "THE" anyway, so you might as well guess "T" and fill in that letter for her now. She might have T's in more useful places than you have. It's important to think about which letters are unhelpful in your words, and which ones you absolutely can't afford to have your opponent find out.
I recommend each player write down all the letters that have already been guessed. This prevents arguments later like "you said K and you didn't write in the K in your own word". Also remember that when your opponent guesses a letter but doesn't fill it into her own puzzle, she's denying having any. So make a note of that.
Note: This game could be expanded to 3+ players too: simply write each player's puzzle on a blackboard and take turns guessing letters (which everyone in the game must fill in, including yourself). Each player scores one point for everyone else's word he/she guesses.