Queens 9x9 grids
Expert level · unlimited grids, size locked.
One queen ♛ per row, column and color. None may touch, not even diagonally.
The Queens 9x9 puzzle
The 9x9 Queens grid is the summit of the game, the expert format reserved for those who already master every technique. Nine queens, eighty-one cells, nine regions with often twisted outlines: nothing is immediate, and a single missed deduction can stall you for long minutes.
At this level, solving is a genuine investigation. You constantly combine every method: direct elimination, confined regions, one-move contradiction tests, and sometimes reasoning chains where you follow the consequences of an assumption across several regions before concluding. Patience and rigor matter as much as speed.
Exhaustive marking is no longer optional but an absolute necessity: across nine rows, visual memory saturates instantly. Every cross saves a future round trip. Work the most constrained regions first, and do not hesitate to clear and restart cleanly if the board becomes unreadable.
Despite the difficulty, the promise holds: the solution is unique and fully deducible, without a single gamble. This is the size of the weekly challenge, the hardest grid of the week. If the 9x9 gives you trouble, consolidate on the 8x8 before returning. The 9x9 grids are free and unlimited.