Slots are the most popular casino games among recreational players. Nice graphics, bonus rounds and jackpot wins draw people to play them.
The properties of slots vary with casino softwares. No software offers slots superior to others but it is good to know about basic types of slots and their different mechanisms.
Reel slots have three to seven spinning reels and one payline at the center. Sometimes you can lock the symbols of non-winning spins. Many of these slots have a bonus feature, which activates when certain symbol lands on one of the reels. Other alternative is that you have to collect certain amount of symbols to activate the bonus feature. This kind of bonus feature is called cumulative as you always know how far you are from getting the bonus round and you can decide whether you should continue to play until you get the bonus round.
The most popular type of slots are video slots. They usually have 5 reels and three rows, so 15 symbols are visible. The player chooses how many lines he plays. Each line goes certain way through the reels. For example line 1 is usually the middle symbols on all 5 reels. Getting same symbols on a win-line from left to right pays according to a paytable. You usually need minimum three matching symbols from left to right for a payout. Some symbols are wild and they can replace for any other symbols making a paying combination. Getting 5 wilds on one of the lines usually gives the highest payout.
In addition to wild symbols there are usually scatter symbols as well. These symbols can appear anywhere on a reel and they don’t have to be on a win-line or left to right to pay out. Commonly three scatter symbols on reels at the same time activates a special bonus feature. The two most common bonus features are certain number of free spins or a pick’em type bonus game. In free spins the reels spin for free for certain amount of spins and the player gets all the winnings. Often all wins are multiplied by 2 or 3 during the free spins, so a large part of the total payout can be in the free spins. Second type of bonus feature is a pick’em type bonus where player picks symbols on screen and gets a random win from each symbol. There are many variations of bonus round this kind.
Bonus feature slots might give an average payout of 65% outside the bonus feature while 30% of the payout is in the bonus feature, totaling 95% payout or 5% house edge. Therefore the player can expect to lose rapidly until he gets the bonus feature (or a high-paying line win).
Progressive Jackpot slots
These are reel and video slots that have especially high payout for a jackpot, which grows without limit until hit at one of the software providers casinos. However the regular payout of the slot is usually lower at ~90% because of the jackpot. The latest (April 2008) big Jackpot of $5,5 million was won on Mega Moolah by a Finnish player.
Strategy and Bonus Play
The player cannot affect the outcome so there is no strategy to slots. But the player can affect bet size and variance of the outcome. Choosing a high-variance slot (like Isis on Microgaming software) the player can risk more for a bigger win. Bet-per-line and number of lines played affect variance. Playing more lines reduces the overall variance but it should be noted that different lines share the same symbols, so playing 2 spins with 10 lines and 1 spin with 20 lines are not exactly the same thing. Most commonly players play 10-20 lines which gives medium variance.
For purposes of playing a bonus on slots, a strategy that increases the EV is to make larger bets at the start and hope for a sizable win. If you win, you can reduce the bet size to complete wagering or switch to a lower variance game. This increases the probability to bust (lose bankroll) but it also increases your chances of making a gain from the bonus. Slots are not very good option for advantage play as the house edge is usually too big. Still there are some bonuses where playthrough on slots has the best expected value or they might be the only game allowed. However, the expected value of these bonuses can be small or negative.
Slots Introduction Video
House Edge and Rule Variations
The house edge of slots is generally between 3-10%. Microgaming, Playtech, and Grand Virtual have published reports showing that their slots pay out 95-96%. Wagerworks reports that their slots have 95-97% return. One exception to mention is casino PAF Online whose Fruit Slot gives 99,65 % return with optimal strategy.
Slots have higher variance than table games and video poker. Non-bonus slots usually have lower variance than slots with bonus rounds. A strategy to use variance to your advantage with a bonus is presented in the strategy section of this game introduction.