For a small while I've had the idea of a [game engine/fantasy console/Scratch clone?] that comes packed with a bunch of example games. The example games should be good enough that people download it just to play them, but they are also encouraged to peek into their source code. I'd hope for it to be a sneaky gateway into programming.

For that, I'll keep this in mind: "Unlucky players may look at the source code of a chance-based effect to check if the odds are actually as stated."