Learn Campfire
Six ways of thinking that pitch every tent. Start with the zeroes — they decide themselves — then pair the edge trees.
How to play CampfireA one-minute video walkthrough is on its way.
- "0" means grass everywhere
- No tree, no tent
- Tents need elbow room
- One tree, one tent
- Count the rows down
- Grass is free
1. "0" means grass everywhere
A row or column with a 0 holds no tents — grass every clearing on sight and move on.
A "0" on the edge is the simplest thing on the board: that row or column holds no tents, so every clearing in it becomes grass the moment you see it. Don’t think, just mark. Those grass cells matter — each one is a clearing you never have to consider again, and they shrink the open sets the count-closure rule works with.
Zeroes also shape the trees. A tree sitting in a zero row or zero column can only take its tent from the other direction. When you’re stuck, look at what the zeroes rule out rather than what the other numbers demand.
2. No tree, no tent
A tent must stand beside a tree. A clearing with no tree next to it can never hold a tent — grass it.
Every tent stands beside a tree — that’s the deal the puzzle makes with you. So a clearing with no tree on any of its four sides can never hold a tent, no matter what the counts say. Grass it on sight. On a 6×6 board this one rule often clears a third of the clearings before you’ve counted a single row.
Make it a habit at the start of every puzzle: sweep the board once for treeless clearings and grass them all. It’s the cheapest information in the game, and it turns vague rows into countable ones.
3. Tents need elbow room
No two tents touch, even diagonally. Pitching a tent turns all eight neighbors to grass.
No two tents touch — not side by side, not corner to corner. The moment you pitch a tent, its eight neighbors are grass, no exceptions. This is the rule that turns one placed tent into a ring of decided cells, and it’s why tents are the most informative thing you can place.
It also works as a weapon in reverse: if pitching a tent on a clearing would touch an existing tent, that clearing is grass. When you’re weighing a candidate, check its eight neighbors first. A surprising number of "maybe" cells die the moment you look around them.
4. One tree, one tent
A tree with a single open neighbor takes its tent there; a tree with its tent grasses the rest.
Each tree gets exactly one tent on one of its four neighboring clearings — no more, no less. Two readings fall out of that. First: a tree with only one open neighbor takes its tent there, immediately. Second: a tree that already has its tent turns every other neighbor to grass.
Trees on the edge are the kindest: they have only three neighbors to begin with, and a corner tree has two. Pair those early. And watch for the quiet contradiction — a tree with two neighboring tents can’t be satisfied, which means something you placed earlier is wrong.
5. Count the rows down
Need minus placed equals open: a row whose remaining tents exactly fill its open clearings pitches them all; a met count grasses the rest.
The counts are arithmetic, and arithmetic is relentless. For any row or column: tents still needed equals the count minus what’s placed; open clearings are what’s left to choose from. When those two numbers are equal, every open clearing holds a tent. When the placed count already meets the number, everything else is grass.
Count routinely, not just when stuck — after every tent you pitch, re-check its row and its column. The game is mostly this loop: place, count, grass, repeat. Players who count after every move finish twice as fast as players who count when stuck.
6. Grass is free
Marking impossible clearings costs nothing and narrows everything. Grass early, grass often — a board of grass is a board half solved.
Grass is free and it never lies. Every clearing you rule out narrows the rows, feeds the counts, and starves the trees of options — which is exactly what forces the deductions. Most of the game is ruling cells out; the tents almost place themselves at the end.
If you take one habit from this guide, take this: when in doubt, grass. A wrong tent poisons the board silently, but a wrong grass mark announces itself — the counts stop adding up and you know exactly where to look. Mark boldly; the puzzle will correct you.
Try them out: play Campfire. Watch the counts: every tent you pitch narrows its whole row and column.