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Comment by stinos | Hacker News Reader

slot tech

Do you mean the 'digital' ones i.e. the games with 3 or 4 3x3 rasters where one has to place 3x1 lines and try to match the fruits and bells and whatnot? If so could you share some knowledge on how the randomization on these things work? When I play these I can't help but wonder how this works. I'm fairly sure it's not 100% work of a random generator but rather finely tuned to give enough so the player comes back, but not too much. And at the same times there's a weight assigned to certain piecs and combinations thereof. And possibly there's even some rules like 'max number of points per x games can be no more then y' etc. All in all, it feels pretty complicated but I might be completely wrong.

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The magic is US Patent 4,484,419. Known in the industry as the "Telnaes" patent after it's inventor.

https://patents.google.com/patent/US4448419A

This invention is where slots migrated from physical reels to virtual ones. A reel could now have thousands of "stops" compared to 10 or 20 on the older machines. The physical reels were now driven by stepper motors to show the landing position of that virtual reel. Having virtual reels with many more stops also meant the jackpots could be a lot higher than the typical 1-in-20^3 possibility of a physical reel group.

After some time, it was realized that the careful design of these virtual reels is where the slot designer can create many many "oh-so-close" combinations of the physical symbols without making the player land any closer to the jackpot than normal. And that semi-positive reinforcement draws the player in to play more.

One of the most recent Planet Money episodes, #773: Slot Flaws Scofflaws, explores slot machine design, to some extent. It's a fun listen.

http://www.npr.org/podcasts/510289/planet-money

Only digital yes although some have physical reels but the actual reels are just for show they have no actual effect even if you move them (it will show reel tilt).

The lower the award the more symbols are on a reel, there are also virtual stops since a reel would need to have a diameter of 2 metres to fit them all on. Blank spaces are also stops. There is only one top award symbol on each reel.

Some slots alter the odds the higher you bet but those are not really common or at least we never had such slots.

I wasn't involved in that much detail to know how each slot machine OS worked other than get the machine working so it can be played. But generally speaking there are multiple PRNGs on old terminals new HD/CF based slots would have similar in software. Nothing is truly random of course, hence the pseudo part, due to limitations of the hardware and the crystal oscillators chips or software used to generate random numbers.

It's random enough although it very common to see a hold of over 100% and way under the optioned in percentage. Usually the higher the denom the higher the payback to the player e.g. 1 cent maybe 80% and $1 95% and $5 may be 98% but those are over one or ten million spins not per player.

Then add in progressives which add to the percentage so a 1 cent progressive at 80% + maybe 5% for the progressive math makes 85% payback. Recently random progressives that award for no reason i.e. you don't need the top five symbols at max bet to win. Some progressive award within a range starts/resets at say $500 won't go over $1000 so if it's $999 it will go soon (people fight over them at that point).

This doesn't include server based slots where the theme (the game e.g. Miss Kitty, Joe's Yard Games, Lobstermania) itself can be changed or the percentage can be altered by hour, by day by player. We never used server based slots but all casinos use a casino management system (CMS) backend to track players and awards points if they have a card and I mean each spin each bet per second every second all is captured. Award points for example may be 40:1 dollars:points it's ridiculously bad you end up paying $400 for a $10 t-shirt in the gift shop.

You may find a Paytable and Reel PAR Sheet interesting https://www.google.com/search?safe=off&biw=1920&bih=1050&sit...:

Delphi has a slot tech forum too. Randy Fromm is another big name he runs Slot Tech Magazine. Randy may even read HN, Mr Fromm are you there?

The industry is amazing right now so many acquisitions. Former slot giant IGT (USA) a huge company was bought by Spielo (Canada) but Spielo was bought by Atronic and Atronic (Monaco) was bought by LottoMatica (Italy). Bally bought Shufflemaster and Scientific Games bought Bally.

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