"Provably fair" gambling with that sort of guarantee has been standard in the Bitcoin world for a few years now.
Of course, the ethically-challenged are endlessly creative, so there are cons you can do with that too - e.g., biasing any numbers the player didn't grab the hash for: https://bitcointalk.org/index.php?topic=948965.0
In my experience (I could be wrong) most provably fair bitcoin gambling games don't require user interaction. It's just a seed that has a deterministic output. This type of provably fair is a different beast, as far as I can see.
Of course, the ethically-challenged are endlessly creative, so there are cons you can do with that too - e.g., biasing any numbers the player didn't grab the hash for: https://bitcointalk.org/index.php?topic=948965.0