- with billions of code combinations, plus 1,424 different game settings and computer A.I.

to start playing the Online Mastermind game.
to download a FREE PC version of the Mastermind game.

Welcome to Chow Ka Fat's "Three-way Artificial Intelligence Mastermind" Web Page, the most feature-rich on-line version of the board game classic. (Or being another classic itself?)



-There are billions of possible code combinations (or permutations, using the proper mathematical term). You have to take a life's (or several lives') time to break all the codes.

-There are altogether 1,424 different game settings to suit players of different levels.

-You may choose to be the Codebreaker or the Codemaker. You may also choose to watch the computer play with itself. (Hence the phrase "Three-Way" in the title of this homepage.)

-Equipped with Artificial Intelligence (A.I.) of this programme, the computer can break the most difficult code using an incredibly small number of steps within seconds! (Believe it or not?)


Due to the notorious (and disgusting) incompatibility between different browsers (or even between different versions of the same browser), I have written two versions of the Mastermind game using two script languages - JavaScript and VBScript. The JavaScript version has fewer graphical features and thus runs faster. It is supported by all browsers. The VBScript version has more graphical features, but is only supported by some browsers. Now click one of the following buttons to start the game:

N.B. If your browser does not run the online version properly, then click HERE to download one of the PC versions of my Mastermind and then play the game.

Some Tips

For beginners: choose the most elementary game setting (No. of colours: 5; Start from: Trial 1; Length of code: 3; Hints contain error(s)?: No error; Order type: Fixed order; Colour repeated?: No repetition). There are only 10 possible secret codes under this setting.

For those who want challenges: choose the most difficult game setting (No. of colours: 10; Start from: Middle; Length of code: Unspecified (3 - 8); Hints contain error(s)?: May contain error(s); Order type: Random order; Colour repeated?: May be repeated any times). HEALTH WARNING: Do not guess blindly. There are as many as 214,356,000 possible secret codes under this setting!


For a detailed introduction to the Online version of my programme, some notes about the A.I. of my programme as well as some links to other Mastermind sites, please click HERE.


You may download the PC versions of my programme with full multimedia and graphical features. As the programmes are stored as zipped files, you will need the Winzip / WinRAR or any built-in unzipping programme to upzip the file. To cater for different PCs, I have prepared four versions for you to choose. Two are written in Flash MX 2004 with ActionScript (Flash Versions 1 and 2) and the other two in Visual Basic 5 (VB Versions 1 and 2). Flash Version 1 is executable on a usual PC without the need of installing any plug-in programme while Flash Version 2 can be run only after your PC has isntalled the Shockwave Flash programme. VB Version 1 is equipped with a full range of background music and sound effects but may not be executable on certain PCs as it requires some plug-in programmes while VB Version2 does not have these features but is executable on a usual PC. Before downloading, you may wish to read the detailed introduction to the features of these PC versions: INSTRUCTIONS ON PC VERSION MASTERMIND (FLASH) or INSTRUCTIONS ON PC VERSION MASTERMIND (VISUAL BASIC).

N.B. As I may modify the programme from time to time, the release dates of the two PC versions are given below so that the users may know which version is the most up-to-date version.

Here are the step-by-step instructions for downloading my programme.

  1. Open a new directory in your PC for storing the unzipped files.
  2. Choose any of the following:

    Release Date:
    29 Jul 2013

    Release Date:
    29 Jul 2013

    Release Date:
    29 Jul 2013

    Release Date:
    29 Jul 2013
  3. Your browser will then prompt you to save the zipped file. Save the file in the directory created in Step 1.
  4. Use the Winzip / WinRAR or any built-in unzipping programme to unzip the files which should be stored in the same directory created in Step 1.
  5. You may then double click the file named Flash_Mastermind.exe / Flash_Mastermind.swf / VB_Mastermind1.exe / VB_Mastermind2.exe and start playing. If you encounter any difficulties, it may be because your PC lacks some essential files for running my programme. Take notice of any error messages and record the names of any file in the message and then send me an email. I will then send you the necessary files that are missing.
  6. For detailed instructions about the game, please read the HTML file named Flaintro.html or Vbintro.html.
  7. Enjoy the game and drop me a mail if you like it.


Mastermind is a game of logical reasoning. Provided that the Codebreaker has the ability of making rigorous logical reasoning, sufficient prudence and patience, he / she can surely break the code. In the following webpages I provide the novice Mastermind players with some Mastermind codebreaking strategies. However, I have to say that there are many ways to break Mastermind codes. What I introduce are not the only methods, nor are they meant to be the quickest codebreaking methods. Nevertheless, if the Codebreaker adopts the strategies I introduce, they can then break the codes in a systematic way. Moreover, the strategies are applicable to any game setting and no preparation work is needed. As a matter of fact, these are the strategies used by my programmes.

In a summary, the strategies I adopt is to assume a possible code first and then make modification to the assumptions according to the hints provided by the Codemaker. Each time only the least possible modification is made to the previous assumptions and the assumptions must remain consistent with the hints given (i.e. no logical contradiction should exist). The process repeats itself until the code is broken or inconsistencies are found among the hints.

Note: To facilitate easy discussion, I use digits to represent colours in the following webpages. Now please click the following links:

Go to My Mastermind Website (Chinese Version)
Go to My Personal Homepage (English Version)
Go to My Personal Homepage (Chinese Version)
Go to My Forum
Please send me any comments or detection of errors at

You are now invited to visit my Guest Map. Please click the "View my Guestmap" button below.
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