Tree and tent pairing
Place isolated tents and match every tree to exactly one adjacent tent.
Logic & rule checking
- Players
- 1–3
- Time
- 15–25 minutes
- Materials
- Printed puzzle, pencil and separate host key
Prepare
Use the 4×4 grid. Trees are B1,D2,A4. Row totals for 1,2,3,4 are 1,0,1,1; column totals A,B,C,D are 1,1,0,1. The totals count tents, never trees. Leave the tree cells fixed.
Follow the rule
Place exactly three tents in empty cells. No pair of tents may touch by an edge or corner. Each tent must be assigned to one orthogonally adjacent tree and each tree used exactly once.
Check each step
A tent may happen to touch a second tree, but its assignment still uses only one. Merely showing that every tree touches some tent is insufficient if two trees claim the same one. Draw the three assignment edges.
Worked example
Try tents A1,D3,B4: pair A1–B1,D3–D2,B4–A4. All row and column totals agree. C2 is forbidden by column C total zero; a tent on D2 is forbidden because a tree already occupies it.
Finish and adapt
Check counts, separation and the complete one-to-one assignment before stopping. This is a small manual training board with one supplied solution, not an automatic generator or a uniqueness proof. Partners may use paper T tokens instead of cutting small tents.
Purpose, observation and provenance
Within this activity: Place isolated tents and match every tree to exactly one adjacent tent.
Check each constraint independently rather than compare only with the sample answer.
Our rules, examples and printable diagrams are separately prepared. The earliest inventor of the broader mechanism is not established here.
Official mechanism reference / 官方机制规则 — Background rules only; all small boards, examples and explanatory text are prepared for this kit. No publisher artwork is reproduced.
Free alternative: Copy the supplied grids, labels and cards onto reused paper. No specialist product is needed. Adults may prepare pieces or act as a scribe.
Printable materials
Preview at 100% scale, with browser headers and footers off. Cut with suitable help. Keep host keys separate. This is a manual tabletop kit, not an online opponent, automatic judge or solver.
Tree and tent pairing · Player sheet
Before you begin
- Use the 4×4 grid. Trees are B1,D2,A4. Row totals for 1,2,3,4 are 1,0,1,1; column totals A,B,C,D are 1,1,0,1. The totals count tents, never trees. Leave the tree cells fixed.
- Place exactly three tents in empty cells. No pair of tents may touch by an edge or corner. Each tent must be assigned to one orthogonally adjacent tree and each tree used exactly once.
- A tent may happen to touch a second tree, but its assignment still uses only one. Merely showing that every tree touches some tent is insufficient if two trees claim the same one. Draw the three assignment edges.
| Row / column | Tents |
|---|---|
| 1 / 2 / 3 / 4 | 1 / 0 / 1 / 1 |
| A / B / C / D | 1 / 1 / 0 / 1 |
T = tree. Write a tent as △ and draw its tree assignment.
| Proposed cells / boundaries | Constraint checked |
|---|---|
| ________ | ________ |
| ________ | ________ |
| ________ | ________ |
Tree and tent pairing · Host key — keep separate
A1↔B1,D3↔D2,B4↔A4; tents A1,D3,B4 meet all totals.
Read the rules as well as this example. Other valid solutions may exist for the puzzle boards. This key is not a claim of uniqueness or measured learning gains.
| Constraint / action | Evidence / correction |
|---|---|
| ________ | ________ |
| ________ | ________ |
| ________ | ________ |
| ________ | ________ |