[joezydeco]

The "time threshold" is the lifetime of the machine. Not minutes, hours, or days.

Slots are fixed to a given payout percentage and then locked in with the gaming board. Traditionally this means a copy of the program is checksummed and stored offsite with the gaming commission. The officials have the right to open that machine at any time and verify that the program matches what is on record.

Casinos cannot dynamically change this payout percentage on the fly. That's a violation of the law. A casino is required to have a certain average payout across all machines, but that does not mean a particular machine needs to obey that percentage. In fact, the penny slots will be set way lower and the high-denomination slots will be set much higher. The average will hit the target.

The "hack" is theft, plain and simple. Putting aside the ability to re-award jackpots, the player found a way to change denomination of credits post-play. This is the equivalent of winning at a table game and then swapping your $1 chips for $100 chips when the dealer is not looking.

[josho]

My source to the dynamic payout ability is a past co-worker that did work in the casinos back office computer system (think big iron computing). He entertained me with stories of how the casinos manipulated the environment to manipulate you into giving them more of your money. So, I may have misunderstood some of the details. But, am curious where your certainty comes from to see who's closer to the truth here.

Regardless, when a machine pays out in a way that is against the house, my take is that these guys deserve every cent they earned. The gamblers did nothing that the casinos don't do everyday. That is, use the rules of the game to their advantage (ie. manipulate you to make a decision against your own best interest). In this case the rules of the game were broken in an extremely subtle way.

[joezydeco]

My certainty comes from nearly a decade writing software for slot machines and consulting to various gaming firms in the United States.

When you say your friend's casino "manipulated the environment" to extract more money from patrons, that's a bit vague. Is he referring to things done to patrons outside the domain of the slot machine (e.g. comped alcohol/rooms/food, awarding extra player points, show tickets, etc), or actually changing the performance of a machine while the person is playing?

Because the NV gaming law (the one that most other jurisdictions copy when doing their own) has it plain and clear in Regulation 14.040 Section 6:

"[Slots] must not automatically alter pay tables or any function of the device based on internal computation of the hold percentage"

Now back in the day, the payout percentage target was fixed in an EPROM table, which the gaming board held a copy. Things are a bit more complex now with networked slots. The games are now downloading their code from a central server. A slot floor manager can load a new game into the cabinet with a different payout percentage, but it cannot be done while a player is playing and for a fixed amount of time afterward, and then the game must go offline (and say so publicly) for another fixed amount of time after the new game loads. This time is on the order of 10 minutes or more so a player is guaranteed to know that the game is being changed if a slot floor decides to do this.

Really, a casino really doesn't need to play around with slots to make sure they earn money. The math guarantees it. The casino's job is to make sure the players come and stay as long as possible which seems like what your friend was involved with. There's serious work in collecting all that player data and trying to understand ways to maximize the handle.

[mikeash]

Surely it's the equivalent of winning at a table game and then convincing the dealer to swap your $1 chips for $100 chips for you.