Logic Masters Deutschland e.V.

You've arrived at a forest campground, but the ranger has left behind only a cryptic map. Trees dot the landscape, waiting for campers to pitch their tents nearby. Your task: decode the ranger's log, find every campsite, and fill in the hidden numbers that bring the grid to life.

The Grid: Fill the 9×9 grid with the digits 1–9 so that each digit appears exactly once in every row, column, and 3×3 box.

Trees and Tents: Some cells are already marked as trees. Your job is to pitch tents, place them into some of the remaining empty cells, following campground regulations.

• Every tent must have a tree as its direct neighbor (horizontally or vertically adjacent). Each tent pairs with exactly one tree, and each tree pairs with exactly one tent.
• Campers need their space: no two tents may touch, not even diagonally.
• The numbers printed along the edges of the grid tell you how many tents appear in each row or column. But the ranger was cryptic. Those same numbers serve a second purpose.

The Ranger's Tally: Each clue number outside the grid is also a Numbered Room Look at the first digit in that row or column (from the clue's direction). Whatever that digit is, call it N, the digit in the Nth cell of that row or column must match it. In other words, the opening digit points to its own echo deeper in the row.

Even Ground, Odd Shelter: The forest has a hidden pattern: trees grow on even ground, tents stand on odd. Every tree cell contains an even digit. Every tent cell contains an odd digit.

The Campfire Sum: Some trees bear a small number, the ranger's campfire note. That number tells you the sum of the digit in that tree cell and the digit in its paired tent cell. Use it to narrow down which camper belongs to which tree.

Solver's Tips Use circles (Pen tool) to mark your tent placements. Color each tree and its paired tent the same shade to track the pairings. Shade out cells that can't legally hold a tent to keep the grid clean.

Play more Tents puzzles here
Credit @takmu53 for his Tents puzzle