Summer 2024 🏖️

The Krazydad Discord Community is a new place where you can talk to me, and meet other people who are interested in puzzles. A great place to report problems or mistakes with this website, suggest new features, help me brainstorm and test out new puzzles, get periodic announcements from me, or discuss other deep thoughts. Maybe I'll see you there!

Ripple Effect Puzzles by KrazyDad

Here are hundreds of free Ripple Effect puzzles suitable for printing.

Ripple Effect was originally published in Japan by Nikoli. The puzzle is a sophisticated variation of Suguru, which was invented by Naoki Inaba, a very prolific puzzle designer. These puzzles have very simple instructions, but a very wide spectrum of difficulties, ranging from easy to insanely challenging.

Ripple Effect puzzles are quite different than Sudoku, and a bit different from Suguru, so you'll want to read these rules carefully.

You'll see that the grid is subdivided into containers or cages, anywhere from 1 to 9 cells in size. You need to fill each cage with unique digits, counting up from 1. So for example a 2-cell cage contains the numbers 1 and 2. A 5-square cage contains all the numbers from 1 to 5. If two identical numbers appear in the same row or column, at least that many cells must separate them. For example, if two 3s appear in the same column, they must be separated by at least three other cells that do not contain 3. This unique ajacency rule gives the puzzles their unique cascading character, hence the name "Ripple Effect." Note that unlike Suguru, diagonal adjacency is always allowed.

Each collection is ordered by difficulty, with the easiest puzzles in Book 1, and the hardest in Book 100. If you are new to these puzzles, I recommend you start with Easy, Book 1. If you find the puzzles are getting too hard, move up to Book #1 of the next volume, and they'll get easier again.

Want to save some trees? Try the online version of these puzzles.

SPECIAL THANKS to programmer Phil Bordelon, who originally requested these puzzles and provided significant help in analyzing and debugging them.