Behind the scenes of Cyber Gomoku development

On this page, the developer himself summarizes how the game Cyber Gomoku was born and the behind-the-scenes aspects of its design and implementation. Introducing how to play the game and the screens Official game introduction page, The exact specification of the rule is Rules/ability list Please take a look. What we're dealing with here is "Why was it made this way?"

Starting point: the limits of the perfect information game

Traditional board games such as Gomoku, chess, and shogi are "perfect-information games" in which all information on the board is disclosed to both players. While it is very fair and highly competitive, the difference in ability is directly linked to winning or losing, and beginners who do not know the basics of the early stages will hardly be able to beat advanced players. I'm sure many of you have had the experience of playing Gomoku for the first time in a while and not being able to talk to friends who know more about it.

On the other hand, one of the reasons why many players are so passionate about modern digital games (FPS, MOBA, etc.) is the concept of "Fog of War." Add in the incomplete information of not knowing where your opponent is, and a drama of reversals is born that mixes reading, bargaining, luck, and strategy.

“If you add the element of incomplete information that can only be realized digitally to the extremely simple rule of Gomoku, Even beginners can aim for a one-shot reversal, and advanced players will find a completely new way to read each other." This hypothesis was the starting point for Cyber Gomoku.

How “invisibility” changes the game

The biggest feature of Cyber Gomoku is that not all stones on the board are visible. In normal Gomoku, if your opponent makes a four-reach attack, you will always notice and defend. However, in Cyber Gomoku, if one of your opponent's quads is stealthed, you will only see three of them on the board. Even though you are in a situation where you will lose if you don't defend, the pressure of not realizing this and potentially hitting somewhere else stays with you throughout the game.

As a result, it is no longer a game of memory where you have to memorize a set formula, but a game where you have to ``infer where your opponent placed the stealth from the way they hit.'' A psychological game (bluffing and guessing) similar to poker is born. What is important in the design is that this anxiety does not become unreasonable. By preparing a counter means called radar and making the bomb risk involving one's own stones, We have adjusted the "invisible elements" so that it does not become a one-sided game of luck. The details of this adjustment are Item balance design article It is explained in.

Three abilities and sources of ideas

Stealth Stones — from submarine sonar warfare

It is a Go stone that disappears from the opponent's screen from the moment it is hit. The idea is military stealth technology and submarine sonar warfare. Just saying ``I can't see it'' makes the other person suspicious, and they end up placing stones in unnecessary places. Even if you don't actually put it there, The true strength of this item is that the very possibility that it may have been left behind acts as a deterrent to the opponent.

Go Stone Bomb — Destroys the “stones you place don’t move”

It has the ability to blow away the surrounding Go stones, regardless of whether they are friend or foe. This was introduced to break Gomoku's basic premise that "a stone cannot be moved once it has been struck." Even if you are surrounded by your opponent and the board appears to be ``losing,'' you can reset the game with just one bomb and regain control. This is a special device for reversals to ensure that the match continues until the end.

Goishi Radar — Countermeasure to Stealth

It is the ability to scan a specified area of the board and discover hidden Stealth Stones and bombs. Prepared as a counter to powerful stealth. The exhilarating feeling you get when you shoot your radar at a spot where you feel your opponent's batting style is unnatural, and your reading is correct and reveals your opponent's aim. I think it's an experience unique to this game.

Technical challenge: “Incomplete information AI” running in a browser

In addition to online battles, Cyber Gomoku has a battle mode against AI (CPU). However, it was not possible to apply the usual GomokuAI algorithms (minimax method and alpha-beta search) as is. This is because there are elements that fundamentally change the board, such as stealth and bombs, which makes designing the board evaluation function much more complex.

In the implementation, we kept the board data in a lightweight format so that it could move quickly even in a single-threaded browser environment, and adjusted the balance between search depth and response speed. At the highest difficulty level, the AI will predict the player's stealth placement to some extent and use radar intentionally. Incorporates heuristic-based behavioral patterns. The fact that we were able to build an AI that completes its thinking on the player's device without going through a server is This was a great achievement in front-end development using React + Vite.

On the other hand, we do not trust the client and re-verify the outcome of online matches and the number of times items are used. Regarding this "server has the correct answer" design, Development record article I have written about it in detail.

Then go to the portal site

The response we received from the development of Cyber Gomoku was to ``add a strategy unique to digital to a standard game.'' after that Magicians Daifugo(Daifugo x Ikasama) Reference Test(Quiz x Investigative ability) has also been inherited. This site is operated as a portal to publish these original works, and development records are Articles It is published continuously.