Ask the Slot Expert: Changing RNGs in a slot machine

We live in South Florida where there are no regulations from the state as far as the casinos go. We have several Indian casinos and several privately run racinos. I am finding that the slots pay nothing as far as any of the jackpots go and most of the time they pay very little.

I have seen time and again in your column where you say that it isn't possible to change the payoff cycles but one of the Indian Casinos was remodeled and it brought in a whole lot of new customers with good pay payoffs on the machines. Now nothing pays at all. This is in a period of only six months.

Is it possible for the casinos to change the RNGs at anytime based on their need?

Thanks for all the great advice!

I wouldn't say that there are no regulations from the state of Florida on casinos. Florida Statute Title XXXIII Chapter 551, for example, covers the operation of slot machines at racinos. Moreover, the Indian casinos have to follow regulations set forth in the Indian Gaming Regulatory Act.

Now, I never said it was impossible to change the long-term payback or hit frequency of a slot machine. I said that it was impossible to change while the machine was being played, and difficult and time-consuming to change otherwise. On most Class III slot machines, a technician still has to change a chip in the machine to change the long-term payback. Some machines allow new software to be downloaded to the machine from a central server, but those machines are not in many casinos right now. In some jurisdictions, casinos cannot even open the logic drawer (the place where the brains of the machine are stored) and someone from the gaming commission has to do it. And let's not forget the paperwork. Many jurisdictions require notice that a long-term payback has been changed.

On a bingo-based Class II system, the casino has to change the bingo pattern-symbol combination mapping or paytable to change long-term payback. I suppose that it is easier to change the long-term paybacks on the machines based on scratch-off tickets (finite outcome) by changing the parameters of the underlying scratch-off ticket pool.

Though I think I know which casino you're writing about, you didn't mention it explicitly so I'm not sure whether the casino has Class II or Class III machines.

I get many letters like yours. Players say that new slots in a casino are loose to get players hooked on them, then the casinos tighten them up once the honeymoon is over. Contrary to your letter, players usually say that their favorite casino remodeled and now the machines don't pay -- presumably to pay for the renovations. As humans, we're uncomfortable with randomness and we look for a cause for whatever effect we've experienced or think we've experienced.

While I can't rule out the possibility that the casino did indeed change the long-term paybacks on its machines, it's more likely that you are just having a bad streak. It's not unusual for professionals to have extended (year-long and even longer) losing streaks. In addition, players experience only a very small sliver of a machine's total performance. It could be an ATM for other players and you're not around to see or benefit from its generosity at that time.

Finally, let's deal with changing RNGs. Remember that the RNG is just a generator of a random number stream. There is nothing tight or loose about it. You don't change the RNG to change a machine's long-term payback. That would violate the prime rule of the RNG: every number should be equally likely to be generated. If the RNG controlled long-term payback, some numbers would have to be more likely than others.

A machine's long-term payback is determined by its reel layout and paytable. Casinos change the reel layout in the program running the slot machine to raise or lower its long-term payback. (On incredibly rare occasions, e.g. the Stratosphere in Las Vegas, the casino may change the paytable.) Referring back to my second paragraph, casinos cannot change a Class III machine's long-term payback at whim.

Jackpots for all,
John