Play Tents and Trees Online

What Is Tents and Trees?

Tents and Trees (also known simply as Tents or by its German name Zeltlager) is a logic puzzle that has been a staple of pencil puzzle magazines since the late 1990s. The puzzle is played on a rectangular grid that contains a number of trees (🌲). Your task is to place tents (⛺) on the grid according to a strict set of rules, using only logical deduction.

The appeal of Tents and Trees lies in its elegant constraints: every tree needs exactly one tent, no two tents may touch, and the clue numbers along the edges tell you exactly how many tents go in each row and column. These interlocking rules create a satisfying chain of deductions — once you find one tent placement, it often unlocks several more. The puzzle requires no arithmetic, making it accessible to all ages, while its spatial logic can be genuinely challenging at larger grid sizes.

Rules of Tents and Trees

1. One tent per tree. Every tree in the grid must be paired with exactly one tent. The tent must be placed in a cell that is orthogonally adjacent (directly up, down, left, or right) to its paired tree.
2. One tree per tent. Each tent belongs to exactly one tree — the pairing is a one-to-one matching.
3. No touching tents. No two tents may be adjacent to each other — not horizontally, not vertically, and not diagonally. This is the puzzle's hardest constraint and the one that creates the most interesting deductions.
4. Row and column counts. The numbers along the right edge and bottom edge of the grid tell you how many tents must appear in each row and column, respectively.
5. Remaining cells are grass. Every cell that doesn't contain a tree or a tent is grass. Marking cells as grass (shown as a faded dot) helps you eliminate possibilities and is an important part of the solving process.

How to Play Online

1. Choose a difficulty. Pick from Easy, Medium, or Hard. Harder puzzles use larger grids with more trees.
2. Read the clues. The numbers along the right and bottom edges tell you how many tents belong in each row and column.
3. Click or tap cells. Clicking an empty cell places a tent (⛺). Clicking again marks it as grass (·). Clicking a third time clears it back to empty.
4. Use Check. Press ✓ Check to temporarily highlight any incorrectly placed tents.
5. Solve it! When every tent is correctly placed the puzzle auto-completes and shows your time.

Strategy Tips

1. Fill Zero Rows and Columns First

If a row or column clue is 0, every non-tree cell in that line must be grass. Mark them immediately — this is free information that often restricts tents in crossing lines.

2. Find Trees with Only One Option

Look for trees where only one neighbour is available for a tent (the others are blocked by other trees, tents, grass, or the grid edge). Place the tent in the only remaining spot and mark all its diagonal neighbours as grass.

3. Count Remaining Spaces

If a row's clue equals the number of empty (non-tree, non-grass) cells left in that row, then all those cells are tents. Conversely, if a row already has enough tents, fill the rest with grass. Continuously re-checking the counts after every placement is the backbone of efficient solving.

4. Use the Diagonal Rule Aggressively

When you place a tent, immediately mark its eight surrounding cells (that aren't trees) as grass. This often creates a chain reaction — restricting other trees to a single tent placement, which lets you place more tents and mark more grass.

5. Consider Tree-Tent Pairing

Sometimes two trees are close together and share potential tent positions. Think about which matching of trees to tents is actually valid. If pairing tree A with position X would leave tree B with no legal tent placement, then tree A must use a different position.

6. Work the Edges

Trees on the grid border have fewer adjacent cells, meaning fewer possible tent locations. Corner trees have only two options; edge trees have only three. These are the easiest starting points for deduction.

History of Tents and Trees

Tents and Trees is believed to have originated in the Netherlands in the late 1990s. It was popularised through Dutch and German puzzle magazines — in Germany it appeared under the name "Zeltlager" (campsite). The puzzle format quickly spread to international puzzle competitions and is now a regular feature in magazines such as Breinbrekers, Logic Puzzles, and the World Puzzle Championship qualifier rounds.

Unlike many famous logic puzzles that emerged from Japan (Sudoku, Nonograms, Kakuro), Tents and Trees has distinctly European roots. Its straightforward rules and visual clarity made it popular in school mathematics enrichment programmes across Europe. The puzzle has since appeared in numerous puzzle apps and websites, often cited as one of the best "introductory" logic puzzles because its constraints are easy to understand but create rich deductive chains.

The puzzle is sometimes called simply "Tents" in competition settings. In academic computer science, it has attracted interest as a constraint satisfaction problem — researchers have studied its computational complexity and devised efficient solvers using techniques from SAT solving and integer programming.

Tents and Trees vs Other Grid Puzzles

Tents and Trees shares DNA with several other logic puzzle families:

• Nonograms also use row and column counts as clues, but you fill in contiguous blocks rather than placing isolated items that must not touch.
• Minesweeper has a similar "count neighbours" feel, though in Minesweeper you're deducing hidden mines rather than placing items.
• Light Up (Akari) places items that project influence (light rays) and must not conflict — analogous to tents that "block" surrounding cells.
• Queens puzzles share the "no two items may be adjacent or on the same line" constraint, though Queens uses colour regions instead of tree pairing.

Frequently Asked Questions

More Puzzle & Strategy Games

If you enjoy Tents and Trees, try these other free games on our site: