Broken Sign Blog
#025: Rail Pool / Double Back
29 July 2022Double Back is a fun loop genre, but it also makes for an interesting additional constraint in other genres, so here’s a hybrid. I accidentally ended up stealing the region layout from a Detour/Double Back hybrid by wen. Whoops.
Rules: Draw a non-intersecting loop through the centres of all cells. Some boldly outlined regions contain number clues. If a straight loop segment visits any cells of a clued region, its length must match one of these numbers. Each number must correspond to at least one such loop segment. Question marks represent any positive integer, but numbers cannot repeat within a region.
Variant: Double Back hybrid — The loop must visit each region exactly twice.