Curious to see what the average person thinks when they see a game uses provably fair algorithms.
I think the first line, "can't be rigged" is the customary definition, but 'provable' to me means there is an algorithm at the core of the game that can be verified, not trusted.
In mining, that means SHA-256 can verify the hash, and it can easily be seen that it is over the required difficulty number.
Aside from mining, I think Satoshi Dice was an early (maybe the first?) example of provable fairness in bitcoin gaming.