Broken Sign Blog
#118: Cross the Streams (Twilight)
6 September 2023This was my second entry to Logic Showcase #49 on Puzzlers Club, “Twilight Sparkle”. Shortly before the deadline, I had a really cursed idea and wanted to see if I could apply the Twilight variant to a genre where the clues are normally not even part of the grid.
I’m really happy with how this turned out. It’s quite a tough puzzle but there are a bunch of really cool deductions throughout the solve. The rules might be a little confusing, but unshaded clues basically act the same regular Cross the Streams clues, and shaded clues apply to unshaded blocks of cells instead.
I was also wondering if this would work with Coral instead. It provides even stronger constraints on the shape of the shaded region, but the clues are unordered (which could give both more and less control). I might try that out eventually.
Rules: Shade some cells so that all shaded cells form one orthogonally connected area. No 2x2 region may be entirely shaded.
Clues represent the lengths of blocks of consecutive (un)shaded cells within the marked 10x10 area, in the corresponding row or column, in order. An unshaded clue represents a shaded block of cells, a shaded clue represents an unshaded block of cells. A question mark represents one block of an unknown number of cells. An asterisk represents any number of blocks of cells, including none at all.
For two consecutive non-asterisk clues which are both shaded (unshaded), their blocks are separated by exactly one block of (shaded) unshaded cells of unknown length. If the list of clues starts/ends with a shaded (unshaded) clue, there may or may not be one block of shaded (unshaded) cells before/after the block it clues.
Whether or not an asterisk clue is shaded gives no information and multiple consecutive asterisks are equivalent to a single asterisk.