A whole lot has been written about the honesty of land-based slot machines. An excellent article by Steve Bourie is titled, "Are Slot Machines Honest?" and originally appeared within the 1999 American Casino Guide. (It can be found online by searching for the title in Google or Yahoo!.) Physical, land-based slot machines have a great deal of "variations" (being polite) than can deceive the player. Of course, they're all illegal and do not happen. But read the article, closely.
Having said that, online casino slots use an electronic "random number generator" or RNG, operating inside an extremely large computer program that manages the game graphics, the player accounts of those who join the game, the statistics of every hand played, and also more. The random number generator is hard-coded software instructions that don't change. There is absolutely no "sense switch" (see the Bourie article) that can be flipped to give players worse odds. Regarding control parameters, each use of the RNG is the same as the last use, and also will be the same as the next use. The numbers will come out randomly, however the pattern of randomness never changes. This is a true benefit from software-based
playing online slot gambling site casino slots.
Land-based slot machines can also have payout percentages as low as 83%, which is just not true with online casino slots. In online gaming, each machine has the exact same winning percentage as the additional machines. You can see the payout percentages for many online gaming sites, and you shall see which it rarely drops below 95% - that is, the house makes a 5% profit, on the common. Actually, most casinos can document that their payout percentages are in the 97% - 98% range. Consequently you may spend per hour, gamble your $100 stake about 3 times, as well as on the regular it's going to cost you $7.50. But players don't gamble to be average: the true reward is the well-paying win. As well as the well-paying win is balanced, bear in mind, by a number of players who lose and finance that win.
So are online casino slots fair? Yes, they clearly are. The software that operates the games is tested regularly by independent testing laboratories (look for logos at the bottom of the casino website), and no game is individually controllable to be biased. That is a far cry from the specific situation with land-based slot machines, appropriately called "one-armed bandits".
Players get better odds, they get absolute consistency across all games - but nobody can guarantee a win every time. That's just the nature of gambling, and that is included in the thrill.