Killer Cages

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.

Sometimes people just “click,” best friends forever. It happens to digits, too! In some columns, and some rows, certain pairs of digits are inseparable.

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.

More of these combo cages that act as “German Whispers” lines. In this case, some of them are square, and adjacent digits means orthogonally-adjacent, since there’s no way a square would work otherwise. For extra fun, very few of the cages have totals.

These cages are the color of “German Whispers” lines as a reminder that each cage functions as just such a line. Even the two-cell cages function as if they were two-cell green lines. Imagine that they’re green lines, but I’ve helpfully provided the total for all of the digits along the line.

Sometimes I think I should create a separate tag for puzzles so full of cages there’s no other constraint. Like Predator 6, and this one. If I ever do, I should update this text, since it will no longer apply.

The coloring is cosmetic, but I like to think of this grid as a rocket, heading into space. It’s a lot of cages, combining in interesting ways, and might provide a nice solving exercise for someone on a long voyage through space.

As an American, I spend far too much time thinking about urban design. This puzzle prompts thoughts of apartment buildings in Barcelona. They didn’t turn out the way Ildefons Cerda planned, but they’re certainly distinctive.

Lockout Lines can be counter-intuitive, to a point. Instead of the digits between two numbers, you want the digits not between two numbers. Normally you can work out “these are high, so those are low,” but with lockout lines, you could end up with both high and low digits together.

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.