Short answer, no they don’t. The odds of hitting a particular combination on a reel depends on the amount of combination of symbols it has and the RTP. Modern slots will tend to include more lines and different combination lines than the classic slots with just three reels. The more options the fewer the odds of hitting a particular symbol or combination. More combination wins does not mean higher payouts, it might mean more wins per spin, even multiple wins per spin but the payout might still barely cover the bet.
In a typical sot machine the chances of hitting the jackpot are 1 in 64 in just one reel. For a three reel that would be 1 in 262,144. Slots tend to have blank stops or symbols that don’t pay anything near the jackpot image. It is more likely for a player to hit the stops right next to the jackpot, creating the impression that the player “almost” hit the jackpot encouraging the player to keep playing. In reality the odds reset themselves with each push of the button and almost hitting the jackpot has no input on the next round.
Casino games of all sorts have a determined payback percentage, on electronic or online slots that payback is fixed. Some online casinos actually publish the payback percentage on the info section of the slot game. Online reviews of the best paying slot machines will actually tell you the specific payout percentage for each game. This is the percentage of the money that is put in that is eventually paid out to the player. Most online slots will have a payout percentage of 90% or close enough. This means that for every dollar you play on the slot game the casino tends to keep 10% of that and the player can expect to receive 90% back.
This is how casinos make their revenue by keeping the odds slightly to their favor. The only way for the player to come out a winner is by stopping during a winning streak.
Payout percentage is also known as RPT or return to player.
No online slot will ever have a payback percentage over 100%. The minimum tends to be 90% and the max 97%. If a player wants to max out the chances of winning a 97%. In most areas were gambling is regulated the law will require the RPT to be above 75%.
Why do casinos increase or decrease the RPT? While they want to maximize earnings and lower the player odds, they also need to compete with the other online or brick and mortar casinos. This is why online casino make the RPT public and advertise it to review sites. It is the single indicator for players to know which game can offer more value.
RPT is configured into slot machines through the machine’s computer chip. Online slots follow the algorithm from the game developer. It is always safe to double check who the online casino auditor is.
Online casinos usually hire a reputable third party to randomly monitor if their games are rigged or not. These third party companies verify the odds of each game and the random number generator to make sure everything is safe. At the same time, these companies are audited by governmental gambling commissions from countries like the UK. Review sites also play their role by receiving emails from angry players and helping out as conciliators with the online casino. If the casino refuses to resolve or explain the issue with honesty and fairness, the reviewers will make the case public and downgrade the casino’s review grade. Online forums are also a great platform for players to express their discomfort. All these actors and mediums influence the casinos to be transparent in their actions and not rigging the games.