Domino Patch Java Game

Here's my domino patch game. It's a sort of puzzle game where you scramble up the pieces and then put them back together in the original position (you must surely have seen a Rubik's Cube). See below for more detailed instructions.

This is a Java applet, download this jar file and run with "java -jar".

How to Play the Game

The starting position is the solved game which is both the starting position and the final position of the tiles. You click on the arrows in the bottom, left-hand corner to scramble up the tiles. This puts you into the scrambled position. Scramble it up as many times as you like.

Now you have to get it back to the original solved game position that you saw before. The score is only 100 in the solved game but it gradually gets larger as you get more dominoes into the correct position.

To twiddle the dominoes, click on the small, white circles that rotate a pair of dominoes by 90 degrees. They always rotate clockwise so you have to click multiple times to get more rotation. Four clicks takes you back to where you were before.

As you twiddle the dominoes, the white circles move around because only pairs of dominoes are allowed to be twiddled. Thus, to move a particular domino around the patch you must line it up with other dominoes along the way.

To move to different configurations (some more difficult than others) click the star in the bottom, right-hand corner. Remember to take note of the details of the layout before you scramble it up (or just open two copies of the page and keep one in the unscrambled state).

Have fun! Don't get frustrated with it... take a walk outside :-)


The key to this game is to note that if a piece doesn't seem to fit a particular position then no matter how you twiddle it around, when it comes back to the same position it still will not fit.

That is because there are "left-handed" pieces and "right-handed" pieces and one can never change into the other. The first board is easy because the handedness of all the pieces is the same, the second board has a few pieces of different colour but still the handedness it always the same so all you have to keep an eye on is the colour.

The third board is the key because two pieces have a different handedness to all the others and you can think you have it finished but really you need to swap over two of the pink dominoes. Once you understand that it is important to keep track of "left-handed" and "right-handed" dominoes -- the rest should be easy.


Many real life problems relate to parity and the distinction between mirror images.

One example is Chiral Molecules (from Chemistry). In human digestion, right-handed sugar (that is just normal sugar) can make you get fat but left-handed sugar (the mirror image of normal sugar) has less calories and won't make you fat. Some sugars even taste different depending on whether they are left-handed or right-handed.

To Download The Game (and Source)

Download the JAR file and you can run the game as an application on your own machine (without this web page). Unzip the JAR to see the source code. Running as an application lets you resize the game board to fit your screen. This program is released under GPL so you are granted the freedom to copy and modify the source.

Index of Java Games