How do slot machines work?
A slot machine picks a random number, maps that number onto reel positions, and pays whatever its published pay table says that combination is worth. The reels are a display of a decision already made, not the thing making it. Nevada writes the requirements down, and reading the regulation instead of a gambling blog settles most of the folklore. Regulation 14.040 requires every gaming device to "Theoretically pay out a mathematically demonstrable percentage of all amounts wagered, which must not be less than 75 percent for each wager available for play on the device", to determine outcomes solely by chance, player skill or a combination of the two, and to display the rules and the game outcome "in an accurate and non-misleading manner". The clause that kills the most persistent myth is 14.040(6): "Gaming devices must not alter any function of the device based on the actual hold percentage." A machine is forbidden from tightening up because it has paid out too much lately. It cannot be due, and it cannot be punishing you.
The reels are a readout. The regulation that governs them is public, and it is more useful than any guide written about it.
The evidence
| Requirement | What the regulation says | Section |
|---|---|---|
| Minimum payback | Must theoretically pay out a mathematically demonstrable percentage of amounts wagered, not less than 75 percent for each wager available | 14.040(1)(a) |
| What decides the outcome | Solely chance, the skill of the player, or a combination of the two | 14.040(1)(b) |
| Disclosure | Rules of play, amounts wagered, amounts paid and the game outcome must be displayed accurately and non-misleadingly | 14.040(1)(c) |
| No reacting to its own results | Gaming devices must not alter any function of the device based on the actual hold percentage | 14.040(6) |
| Who checks | Independent testing laboratories must register with the Board to inspect and certify devices for use in Nevada | 14.360 |
How we know
Everything above is quoted from the regulator, the Nevada Gaming Commission, in the February 2026 revision of Regulation 14. We went to the primary document because the secondary writing on this topic is mostly affiliate guides restating each other, and the actual text turned out to be both stricter and more specific than the summaries of it. Two things worth separating. The 75 percent floor is a LEGAL MINIMUM, not a typical return: real machines are built well above it, and a floor tells you what is permitted rather than what is offered. And "randomness" has a defined meaning in the regulation, "the observed unpredictability and absence of pattern in a set of elements or events that have definite probabilities of occurrence", which is not the same as every outcome being equally likely. The probabilities are fixed and deliberate; the sequence is unpredictable. Scope, stated rather than implied: this is Nevada. Other jurisdictions set their own floors and their own testing regimes, and the crypto casinos Raw tracks are mostly licensed elsewhere, so do not read the 75 percent figure as a global guarantee. It is the clearest published example of how the rules work, not a promise about your machine.