Gattai

So many movie execs seems afraid to be honest about how many times they’ve gone back to that well for more money. It wasn’t Die Hard 3, after all. This is DoubleDoku 3, and it’s my favorite so far, but now I’m determined to mimic the silly names movie execs have come up with.

I’ll save the punchline for those who solve the puzzle. It’s the end of another month, and so time for another Gattai! This will also bring this run of Renban puzzles to close. For now. I do like Renban as a constraint, but I’ll try to mix things up for a while.

Once a month, I post a Gattai, and usually each grid has a separate constraint. This month, five grids, a full Samurai Sudoku, but they are all classic Sudoku, with diagonal lines the only extra rule. This title is redundant, since 侍 is the character for “Samurai,” making the title “Samurai Samurai Samurai.”

The challenges in creating these larger puzzles are multiple. I could have created more than four single-grid puzzles in less time than it took to create this one, in part because each change required me to re-solve the puzzle from the start, to be sure I hadn’t broken anything unexpectedly. Still, the satisfaction of a working gattai that also follows the rules I’ve set for myself, it’s worth spending the extra time on one out of every dozen puzzles or so.

Overlapping grids are interesting, but I thought: why always align on thick region borders? What if I split them offset? The answer is: it is a much more difficult puzzle to set, but makes solving more interesting. Trivia: When I set my normal logical auto-solver to the settings I like to use for testing, it gets “stuck” at one particular step. So if you solve the puzzle without using the walkthrough, you’ve done a better job than my logical auto-solver! Even more trivial: The renban lines are almost perfectly symmetrical, but there are two differences.

It could have been named “Son of DoubleDoku” or “2 Double 2 Doku” or even “DoubleDoku: Folie à Deux,” but whatever it’s called, it’s a sequel to DoubleDoku.

It’s a big one, and it’s anchored by Gravity Cages at the bottom. While these cages don’t directly affect anything else in the puzzle, I like to imagine they’ll combine to form a black hole, pulling everything in all four grids into a single cell.

Irish pub cuisine, or a Gattai-3 Sudoku puzzle? You decide!

Can I interest you in a fine manufactured home? It’s so wide! Almost, but not quite, twice as wide as a single-wide. In fact, it’s 1.67 times as wide, and 1.33 times as tall as a normal 9x9 Sudoku.

It’s t-t-t-two puzzles in one! For the low, low price of nothing, you get not one, not two, but 1.55 puzzles! It would be two puzzles, but four of the nine boxes are shared, so they probably shouldn’t count twice. One of the two grids is outlined in a shade lighter than the other.