PUZRU combines a compact number-logic puzzle with a shared live race. The board itself has only three core rules, but the live world adds a Discoverer, verified solvers and a continuing Chain between puzzles.
Rule 1: use 1–6 once in every row
Each horizontal row contains the digits 1, 2, 3, 4, 5 and 6 exactly once. If a row already contains a 4, no other cell in that row can be 4.
Rule 2: use 1–6 once in every column
The same uniqueness rule applies vertically. This is the Latin-square foundation of the puzzle and is what turns cage combinations into exact placements.
Rule 3: every connected cage must hit its sum
The small number attached to a cage is its target total. All values in that connected group must add exactly to the target.
How to use notes
Notes let you hold a few candidate digits without committing them. Start with constrained cages, write the plausible values, then remove candidates as rows and columns become more specific.
What does “Submit Solution” do?
A completed board is verified by the server. If your valid solution is the first accepted while the puzzle is OPEN, you become the Discoverer. The world then enters a shared 45-second contribution window.
What happens after the 45 seconds?
The puzzle enters a 20-second transition. The completed solution is shown, the Discoverer is recorded, and six solved values are highlighted because they will become fixed cells in the next puzzle.
Put the idea into practice
The fastest way to understand the interaction between row, column and cage constraints is to solve a board. Start in the 200-puzzle progressive Training Room, then enter the live world whenever you are ready to race for Discoverer.