Unlike the electromechanical machines in land-based casinos, both online and mobile slot games use software to determine the outcome of a spin. This software is based on a random number generator (RNG), which ensures that each “virtual spin” is completely independent of the previous one. The RNG is tested by experts to ensure that it cannot be tampered with or influenced by players or casino employees.

Each game has its own set of rules and paylines, but the basic principle is the same: The reels spin and if certain combinations land, the player receives a payout. Different types of symbols have different values, and winning combinations can also be determined by the amount of money that has been bet on a particular line. Usually, the paylines are arranged on three or five rows and fit 3-5 symbols each. Some slots also have special symbols, such as wilds and scatters, which can substitute for other symbols and increase your chances of hitting a winning combination.

Many people have misconceptions about how online slots work, such as believing that the machines will take advantage of you if you leave them on autoplay for an extended period of time or that they are not fair. These beliefs are false, as both manual and automatic spins work with the same math and the same random numbers are used. In addition, reputable casinos will disclose their payout percentages in the help menu and may even post them on their website.