Wizardry (http://www.milaadesign.com/wizardy.html)
It's always one of a few numbers. Once you have your number, have a look around the board, there are a number of other places where you'll see the same symbol
But you can have different symbols, and it's never got it wrong yet
The symbols aren't the same for each number every time though. The symbol it shows is always the one which corresponds to 9, 18, 27, 36, 45, 54, 63, 72, and 81, because those are the only numbers you can actually have.
This is some seriously cool, yet disturbing, piece of work. Wow!!
I tried it ten times in a row and it got the right answer everytime!!
Very, very cool man. :D
Edit: I just figured it out!! Now that is a neat bit.