Oh brother. We can go on and on about why "true randomness" doesn't exist in computers, but that's besides the point. I studied Linear Congruential Generators for an entire semester, and that topic is as boring as hell.

"Pure" randomness aside, is the roulette wheel weighted? Yeah - I'd be willing to bet that it is. Items appear to have the same probability of being won because of the number of squares they occupy, but I'm willing to bet that, behind the scenes, they're doing some adjustments.