Ripple Effect is a number puzzle game that has a lot of similarities to “Sudoku”, but not nearly as well known. **It requires logical thinking, patience, and the ability to count to 9**. If you have all of that, you are set to play the game.

I’ve written this **Java game** as part of my bachelor thesis (the other part was analyzing the puzzle and determining complexity, comparing solving strategies, aso.). When I find the time I want to fix the minor bugs that it has, e.g. that the help button doesn’t work correctly. Maybe I’ll also turn it into a java applet to allow online playing without first downloading it.

**Installation:**

- Download the zip-file: RippleEffect
- Extract all of its contents to a location of your choice
- Run the “rippleEffect.jar” . If you are on windows, you probably just can doubleclick it to run it. (Better instructions will follow soon).

**The Game:**

Ripple Effect is (usually) played on a rectangular grid of squares. The squares are combined into boxes by thick lines. Some of the squares are already filled with numbers.

**The Rules:**

- There are only two simple rules that define which number can be put into which square.A box (combination of multiple squares) must contain all the numbers from 1 to the size of the box once each. E.g. a box that consists of three squares must contain the numbers 1, 2 and 3.
- A square filled with number
*X*has to be at least*X*squares away from other squares with number*X*, horizontally and vertically (there are no restrictions for diagonal distance). E.g. There have to be at least 2 squares without the number 2 between two squares filled with number 2.

The second rule is the reason why the game is called “Ripple Effect”. Filling in a number at one place affects nearby squares, which in turn will affect squares close to them, etc. The effects of filling in a number spreads like a wave throughout the playing field.

**The Winning Condition:**

To win, every square has to contain a number and the rules 1+2 have to be respected in all cases.