In countries like Thailand and India, it's common to see many Chinese manufacturers dominating the AppStore revenue charts for gambling games. Similarly, in the European and American AppStore revenue charts, many such games are also at the top. In these Western markets, similar to the match-three games in China, playing slots during leisure time to test one's luck has become a lifestyle habit, unlike in China where players often see it as a chance for overnight wealth, with many getting addicted.
As for the prospects in overseas markets, I won't go into too much detail here. Most domestic card game companies are already strategizing for the international market, aiming to secure a foothold. More focus should be on the algorithms, and today I'll discuss two basic types of slot machine games, which nearly all slot machines use, so as to inspire those who are planning to expand overseas and encourage more discussions.
1. Natural Probability Type
As the name suggests, each play's score and expectation are the same. This type of slot machine usually has a set odds table, reel table, and special gameplay rules. Each bet by the player is made with the same probability from the odds table to determine the game outcome. Generally, casinos or slot machines certified by third parties use this design method.
2. Non-Natural Probability
In China, most mobile game manufacturers adopt this method. Simply put, it involves deducing the process from the result. Although it may seem similar in performance, for professional gamblers, the core and experience are incomparable. (This is a quote from a Taiwanese colleague who manufactures physical slot machines and supplies them to various casinos year-round. Although I personally think that proper tuning doesn't make much difference, I've experienced slot machines in casinos like Macau, Genting, and Las Vegas, and I feel that the experience isn't necessarily better than that of domestic mobile games, much of it is due to the atmosphere created by the location.)
Slot Machine Algorithm Explanation:
This algorithm is divided into several types, including those that calculate results using weights, those that simulate real spinning using reels, and those that deduce the process from the result. I have tried each type in previous games, and the effects vary slightly, although the macro data doesn't differ much. Today, let's talk about the most interesting algorithm, the reel type.
The reel type, as the name implies, simulates the spinning of wheels to obtain symbols. The most basic setup involves three reels placed together, each reel painted with a certain number of symbols, and then spun by pulling a lever. If the symbols that appear meet certain conditions, it is considered a win. Here, we simulate the simplest reel for explanation.
We assume each reel has 10 symbols, with only one being a '7' and the rest being non-effective symbols.
Winning condition: If all three reels align with '7' on the winning line, it counts as a win, with a multiplier of 1000 times. All other outcomes are not considered wins.
This forms the most basic reel-type slot machine. Next, we should calculate its winning rate formula and return-to-player rate (RTP, a very important index that directly affects player retention and experience).
Winning Rate Formula:
This means that on average, every 1000 spins, you will hit the 1000 times jackpot once, with a winning rate of one-thousandth.
Average Winning Formula:
Average winning = Prize * Winning rate
According to this formula, when you win a prize greater than 1000 times, the average winning per spin is 1.
Return-to-Player Rate Formula:
RTP = Average winning / Average bet
From the current reel setup, it can be seen that the RTP equals 100%, meaning that as long as I keep spinning, I will definitely not lose, even though the winning probability is very low.
This leads to a discussion on the experience issue. No player wants to play such a slot machine, even if it doesn't make money, because it's too monotonous. Although the essence of slot machines is to win big with small bets, it is based on the player's patience to continue playing for a long time. Therefore, modern slot machines use various combinations of small rewards or special combinations of special gameplay to stimulate players and keep their interest in the game.
Further discussion can be made on how adding or removing symbols affects the RTP, hit rate, volatility, and other elements to enrich a simple reel slot machine.
By adjusting the probability of each symbol appearing on each reel, the game's RTP can be easily controlled. For example, adding another '7' to the first reel while keeping the others unchanged changes the RTP as follows:
You average one big win every 500 plays, and the RTP becomes 200%.
On this basis, you could try adding a second winning rule, such as adding fruit symbols. When three fruit symbols appear on one line, it is judged as a win, with a prize of 500 points.
It can be seen that after this, the RTP sharply increases. To balance the RTP, the number of times players do not hit must be increased, thereby sacrificing the player's experience. Therefore, designing a suitable odds table is crucial for slot machines. For veteran slot machine players, if the odds table and game RTP do not match or the experience deviation is too large, they can easily feel it.
Regarding game experience, volatility also needs to be considered. The uncertainty of the next reward is the most effective way to attract players to play. Each spin could potentially yield a big prize, or after accumulating a certain number of spins, the anticipation grows. If the rewards are always bland, sometimes it's even better not to have any rewards at all. This is similar to the lottery systems in domestic pay-to-win online games, where although most players know the odds are low, they always fantasize that the next SSR will be theirs.
In terms of slot machine design, games with higher volatility have a lower probability of hitting big prizes, and those with lower volatility have a higher chance. Finding the right balance in this aspect requires skill and is a true test of one's numerical abilities.
A well-designed reel slot machine, due to its extremely simple and transparent method, still fascinates many players to this day. However, the basic design ideas and methods have been discussed. More complex slot machine games and additional algorithmic ideas will be shared next time. (The formulas mentioned above refer to materials from overseas designers, and due to the extensive content, only the most basic explanations are captured.)
