(c) In the case of a gaming device, a copy of all executable software, including data and graphic information, and a copy of all source code for programs that cannot be reasonably demonstrated to have any use other than in a gaming device, submitted on electronically readable, unalterable media;
http://gaming.nv.gov/modules/showdocument.aspx?documentid=29...
Makes one imagine what kind of political trench wars probably went on behind the scenes about this regulation.
Edit: On second thought, this seems awfully easy to circumvent. What stops me from making a rigged PRNG and then refusing to make the source code available on the grounds that there are lots of non-gambling applications for PRNGs?
This was true even before electronic slot machines.
E.g., if someone already dumped a lot of money into other games, I can give them above-average odds of winning and be sure I still make a profit (and they make a loss), otherwise I'll give them below-average odds.
If I tune this right, the average outcome over all players will still look "fair".
Or I simply give the above-average play sessions to strawmen.
I could hide the above manipulations in some component I don't have to expose and have the machine play nice under testing conditions. (See certain automakers for examples)