The Reasons You No Longer Find Bonus Accumulator Slot Machines on the Casino Floor


Slot machines are not usually viewed as games that can be beaten. In fact, slots are generally considered one of the worst casino games as far as your odds of winning go.

Slot machines can have a large house advantage, especially in land-based casinos. You may be dealing with anywhere from a 5% to 12% house edge.

Another problem with slots is that you likely play them at a quick rate. This fast play rate, combined with the high house edge, can lead to big losses.

Bonus accumulator slots, on the other hand, are different since they give you a chance to beat the house edge in the long run. The only problem is that it’s extremely rare — if not impossible — to find these games.

What happened to bonus accumulator slots and why did they disappear? I’m going to answer this by covering more on what accumulator slot machines are, why they offer an advantage, and which group of gamblers ruined the entire thing.

What Are Bonus Accumulator Slots?

Many slot machines offer bonuses that deliver large payouts. The average game offers these bonuses randomly, meaning that luck is your only tool for triggering these rewards.

An accumulator differs, though, because it features a bonus meter that measures when you receive a special prize. You essentially “accumulate” these bonuses by earning special symbols during your session.

S&H Stamps is one of the most famous examples of an accumulator slot machine. This game, which is based on trading stamps that were rolled out in the 1930s, sees you collect green stamps to increase the bonus meter.

This meter increases each time that you earn a green stamp. Once you’ve received enough stamps, you can trade them in for a bonus.

Other than the bonus accumulation aspect, these games play just like any other slot machine, where you spin the reels in hopes of winning big payouts. But the bonus meter definitely adds a new wrinkle to the gameplay.

Why Are Bonus Accumulator Slot Machines Great?

Earlier I described how slot machines don’t usually give you a very good chance to win money. But there a few ways that you can win profits with these games.

One way is by finding a large progressive slots jackpot that’s increased well beyond its original starting value. Here’s an example:

  • A slot machine has a starting jackpot worth $10,000.
  • You begin playing the game when the jackpot is worth $100,000.
  • The 10x increase means that the slot could be offering a long-term advantage.

A progressive game’s jackpot can grow to the point where it offers positive expected value (+EV). This is why you can theoretically gain an edge by playing it.

The downside, though, is that you don’t have enough variables to accurately calculate when the slot will offer +EV. Instead, you simply need to guess based on the jackpot’s starting and current value.

One more problem is that you’ll deal with a high amount of variance when chasing larger jackpots. The odds of you winning can number in the hundreds of millions.

This is why some advantage players prefer mystery progressive slot machines. These slots don’t offer very large jackpots, but they still give you +EV value when played right.

Another advantage is that the small jackpots in these games reduce the variance. You can expect to earn more payouts and thus reduce your chances of going bust in the process.

Bonus accumulator slots offer yet another way to win long-term profits. Much like mystery progressive games, you won’t win giant payouts with accumulators.

But you can at least look forward to consistent payouts. Moreover, you don’t need to run any calculations on a bonus accumulator like you would a mystery progressive slot.

Instead, you simply need to walk around the casino and find an empty slot machine that has a near-full bonus meter.

Keep in mind that finding slots with nearly full bonus meters doesn’t guarantee you a profit. You could be playing the game for a while before you finally trigger the special payout.

But consistently finding near-full meters and taking advantage of them will eventually result in a profit. After all, you have an accurate way to predict when bonus payouts will be delivered this way.

Contrast this to a regular slot machine, which randomly awards its bonuses. Seeing as how you have no way to tell when the bonus is about to be paid, you can’t gain an edge with regular games.

Slots Teams Formed to Take Advantage of Accumulator Slot Machines

Any casino game that offers a potential edge is exploited at some point. Therefore, it’s no surprise that slots teams formed to take advantage of bonus accumulator games.

These squads were common over a decade ago, when they were more accumulator slot machines available.

Team members would spread out around the casino and hunt for games with bonus meters that were nearly full. Being a team allowed them to cover more ground and take advantage of additional opportunities.

Casinos have never been welcoming to advantage players. But the difference with accumulator slots teams is that they’re not technically winning anything off casinos.

The house makes profits on these machines regardless of who earns the bonus. As long as enough bets are placed to make the meter reach its max amount, the casino will earn money in the long run.

Contrast this to an advantage play method like card counting, where players are winning profits directly from the house. Casinos don’t offer blackjack under the expectation that they’ll lose, which is why they’re so adamant about stopping counters.

Vultures Began Harassing Other Players

The concept of people forming teams to take advantage of accumulator bonuses doesn’t inherently bother the house. But casinos had trouble with teams that harassed regular customers in order to gain access to their machines.

Here’s a typical scenario on how this played out:

  • A regular customer would play a bonus accumulator slot.
  • The player would increase the meter to the point where it was close to offering a bonus.
  • A team member would see this and try to coax the player off their machine.
  • The team member might tell the player that they really want to play the game because it’s their lucky machine.
  • Arguments sometimes started when the player didn’t want to leave.

These pushy types of bonus hunters became known as a “vultures.” This nickname accurately describes them too, because they hung around accumulator slots like vultures looking for a carcass.

Things grew so bad that fistfights would occasionally break out over vultures and regular customers.

Casinos saw the problem with bonus accumulator slots and vultures. This led to vultures eventually being banned because they caused too much drama.

But this didn’t stop new teams from stepping in to take their place. Casinos finally settled the matter by getting rid of accumulator slot machines like S&H Green Stamps altogether.

These actions ruined the edge that vultures could gain through accumulating bonuses. Therefore, teams eventually left the casinos and the problems subsided.

Casinos Allowed Vultures & Slots Teams — To a Point

You might wonder why casinos didn’t simply ban vultures to begin with. After all, they have no problem kicking out card counters.

The truth is that vultures helped casinos to some degree. I mentioned before that the casino made money no matter who won the bonus.

Sure, slots teams still made long-term profits off these games as well. But teams also contributed more money to the slots in order to “buy” the accumulating bonuses.

The average customer didn’t think in terms of how they were giving up a bonus by stopping their play when the meter was nearly full. They’d sit down to accumulator slots regardless.

Therefore, casinos were basically receiving more play thanks to the vultures. Once the bonus was triggered and reset, the cycle started over with more normal customers playing accumulator machines and moving the meters.

Of course, the main problem came in when slots teams became too pushy and used unsavory tactics.

Asking somebody to use their machine is one thing. But harassing them and hovering around the area is another.

Again, vultures did help by contributing more play to bonus accumulator slot machines. But they weren’t good enough customers to where they could get away with bothering normal players, who ultimately drive casino profits.

Can You Still Find Accumulator Slot Machines?

Bonus accumulator slots were good from the perspective that they offered yet another advantage play method in casinos. What’s nice is that you didn’t have to spend countless hours learning strategy either.

All you needed to do was find out which games offered an accumulating meter. You could then walk around the casino by yourself or with a team and look for these games.

Casinos received a lot of play on accumulator slot machines. Standard gamblers found these games fun from the perspective that they could fill a bonus meter, while teams liked stepping in to finish any vacant meter.

The problem with some advantage players, though, is that they go too far to gain an edge. Such was the case here, with vultures trying to get other players off machines so they could take advantage of near-full meters.

You can’t blame casinos for getting rid of bonus accumulator slot machines in light of this. Handling disputes that arise between vultures and regular customers became a headache that casinos didn’t want.

Most casinos got rid of their accumulators well over a decade ago. Some gambling establishments still had these machines afterward, but they too stopped ordering accumulators as well.

The end result is that it’s impossible to find an accumulator slot machine in Las Vegas. I personally don’t know of any of these games existing in Sin City or beyond.

Of course, I don’t live in Vegas and only visit from time to time. But from what I’ve read online, nobody else comes across these games either.


Accumulator machines are definitely fun from the perspective that they give you the opportunity to enjoy slots in a new light. Instead of simply triggering random bonuses, you can fill a meter by collecting special items during the game.

It’s unfortunate that accumulator slots are long gone from casinos. But it also makes sense why gambling establishments got rid of them.

They simply caused too many problems between normal customers and pros who were looking for an advantage. Vultures especially ruined things by hovering around machines and harassing good customers.

In the end, casinos felt that the best decision was to get rid of accumulator machines and rely on other games to make money.

Considering the growth of the Vegas casino industry, it doesn’t seem like they made a mistake either. Attracting and retaining good customers is far more important than a special type of slot that can bring in profits.

But is there a chance that we might see accumulator slot machines in the future?

The answer is probably not, because the same problems would arise again. These slot machines will remain a footnote in gaming history.

Nevertheless, the era of bonus accumulator slot machines was definitely an interesting time. But it was a necessity that accumulators were done away with due to the headaches they caused casinos.

Petko Stoyanov
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About Petko Stoyanov
My name is Petko Stoyanov, and I've been a gambling writer for more than ten years. I guess that was the natural path for me since I've loved soccer and card games for as long as I can remember! I have a long and fairly successful history with English Premier League betting and online poker, but I follow many other sports. I watch all big European soccer leagues, basketball, football, and tennis regularly, and I keep an eye on snooker, volleyball, and major UFC events.