# Casoual Games — full content

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---

# The history of Snake — from Blockade to .io

Source: https://snake.casoual.games/history.html
Game: Snake — https://snake.casoual.games/
Language: en

In short. The mechanic first appeared in Blockade , a 1976 arcade game by Gremlin Industries. It spread through home computers under a dozen names, then reached an enormous audience in 1997 , when Nokia put a version by Taneli Armanto on the 6110. In 2016 , Slither.io replaced the walls with other players — and turned a solo score chase into something closer to a predator game.

## 1976: two snakes, no apples

Blockade was a two-player arcade game. Each player left a solid trail behind them, and the loser was whoever hit a wall or a trail first. There was nothing to eat — you grew automatically, and the board filled up until someone ran out of room.

That is worth pausing on, because it is the pure form of the idea: the thing that kills you is the space you have already used . Every later version is a variation on that sentence.

Blockade was cloned within months, and the mechanic escaped into the home computer era with no clear owner. It is why Snake has no canonical author and why the name changes everywhere you look.

1976 — Blockade
Gremlin Industries. Two players, growing trails, no food. The mechanic in its rawest form.

1977–1982 — the clones
Worm, Surround on the Atari 2600, Nibbler in arcades. The apple appears in this period: food gives the player control over when they grow.

1982 — Tron
The light cycle sequence takes Blockade's idea back to the arcade, and gives it the image most people still picture.

1997 — Nokia 6110
Taneli Armanto adapts Snake for a phone with a 84×48 pixel screen. It ships on hundreds of millions of handsets and becomes, for a decade, the most played video game on earth.

2016 — Slither.io
Steve Howse replaces the walls with other players. Dying leaves your mass on the ground for someone else to eat.

## Why the Nokia version mattered so much

Snake on the 6110 was not the best version of the game. It mattered because of where it was: in a pocket, always, with nothing else on the device competing for attention.

It also had the perfect shape for that context. No loading, no save, no story, a single button of input, and a session that ends whenever you need it to. Those constraints came from a 84×48 screen, but they describe what a phone game should be well enough that people are still rediscovering them.

The design lesson that survived
Snake's difficulty comes entirely from the player's own success. You are not fighting a level designer — you are fighting the length you earned. That is why it never needed balancing, and why it survived thirty years of hardware changes without a single mechanical addition.

## 2016: when the walls became other players

Slither.io changed one thing, and it changed everything downstream. The hazard is no longer the border of the screen or your own tail — it is the other snakes. In doing so it founded what are now called .io games : free browser games where everyone shares one persistent arena, named after the .io domain the first of them launched on.

Three consequences follow, and they are what make the arena version a different game rather than a bigger one:

- Being long stops being purely good. Length is still power, but it is also a bigger target and a slower turn. In classic Snake, long is simply closer to death by your own tail; here it makes you visible.

- Death feeds the ecosystem. A dead snake drops its mass, so the biggest opportunity on the board is always someone else's mistake.

- You can hunt. Cutting in front of a larger snake kills it outright. Size does not protect you from a small, fast opponent with better nerves — which is why the arena rewards patience over greed.

This version keeps that structure: an arena you share, a boost that costs mass to use, and nineteen bots when you play alone so the board is never empty.

### How to survive longer in the arena

- Circle, don't chase. Head-on pursuit of a snake your size loses more often than it wins. Curving around one that is already busy eating is how kills actually happen.

- Boost costs mass. It is an escape tool and a finishing move, not a way to travel. Boosting to reach food usually costs more than the food returns.

- Take the edge early. The border limits the directions you can be attacked from, which matters far more when you are small.

- Let a fight finish before you arrive. The mass from a kill stays on the ground. Arriving second is often better than arriving first.

## Frequently asked questions

### Who invented Snake?

Nobody owns it. The mechanic first appeared in Blockade, made by Gremlin Industries in 1976, and was cloned so widely that no single author is credited. The famous mobile version was adapted for Nokia by Taneli Armanto in 1997.

### What was the Snake game on old Nokia phones?

A version written for the Nokia 6110 in 1997 and shipped on hundreds of millions of handsets through the following decade. Its 84×48 pixel screen forced a design with no loading, no saving and one button of input — which is roughly what a good phone game still looks like.

### What is the difference between Snake and Slither.io?

In classic Snake the hazards are the walls and your own tail, and you play alone against a score. In the arena format the hazard is other players: you die by running into them, you can kill by cutting across their path, and a dead snake's mass is left on the ground for others to eat.

### Does being the biggest snake mean you win?

No. Length gives you reach and mass, but it also makes you a larger target and slows your turns. A small snake that cuts in front of a large one kills it outright, so size is an advantage without being protection.

### What is a .io game?

A free browser game where every player shares one persistent arena — the format Slither.io founded in 2016, named after the .io domain it launched on. Snake arenas, Agar-style cell games and their many cousins all descend from it.

### Why does Snake get harder as you play?

Because the obstacle is your own success. Every point you score lengthens the tail you then have to avoid, so the difficulty curve is produced by the player rather than designed. It is the reason the game never needed levels or balancing.

## Play Snake

Solo against nineteen bots, or in a live arena with real players. Free, no account.

Play now
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Related guides: Racetrack, the paper racing game ·
how to win at 2048

Snake is part of Casoual Games , a one-person studio.
More guides and rules for the other games.

---

# Racetrack, the paper racing game — rules and how to play

Source: https://dotrace.casoual.games/racetrack.html
Game: Dotrace — https://dotrace.casoual.games/
Language: en

In short. Racetrack is a two-player pencil-and-paper game played on graph paper. Each player draws a circuit, then moves a car one grid point at a time. The catch is that your move is a vector : whatever direction and speed you had last turn carries over, and you may only adjust it by one square horizontally and one vertically. Leave the track and you lose a turn. First car across the finish line wins.

The game was invented in the 1960s and reached a wide audience through Martin Gardner's Mathematical Games column in Scientific American , January 1973 . It has been rediscovered many times since, under names like vector racing or, in French, jeu de course papier .

## What you need

Graph paper, one pen per player, and two minutes to draw a circuit. Draw a closed loop — any shape, as long as it has an inside and an outside — and mark a start line across it. Wide corners make an easy track; tight hairpins make a cruel one.

Each car starts on a grid point on the start line, at a standstill.

## How a move works

This is the whole game, and it takes one paragraph.

Your car has a velocity : how many squares it travelled horizontally and vertically on the previous turn. On your turn, you may change each of those two numbers by at most one . Then the car moves by the new velocity, and you mark the new point.

previous velocity (3, −1) → 3 right, 1 up
allowed next (2…4, −2…0)
you pick (4, 0) → the car travels 4 right, 0 up

From a standstill, your first move can only be one square in any direction — including diagonally. From there speed builds up one square per turn, and that is where the trouble starts: a car doing six squares a turn needs six turns to stop, and cannot turn sharply at all.

### Leaving the track

If the straight line between your last point and your new one crosses the edge of the circuit, you have crashed. The usual penalty is the gentlest one: your car returns to the last point that was on the track, its velocity resets to zero, and you miss a turn. Harsher house rules exist — some groups simply eliminate you.

Two cars may not occupy the same grid point on the same turn. Beyond that, they do not collide: this is a race against the geometry, not a contact sport.

## The one thing that makes it interesting

Because you can only change speed by one square per turn, braking has to be planned several turns before the corner . A beginner accelerates down the straight and arrives at the hairpin doing seven squares a turn, with no legal move that keeps them on the track. The skill of the game is not steering — it is knowing, four turns early, what speed you will need.

That is also why the game rewards taking the racing line. Cutting a corner tightly costs you speed on the way in; going wide keeps your velocity but travels further. It is the real trade-off of motor racing, produced by a rule you can write on one line.

A quick way to get better
Before each move, ask what velocity you want to be carrying when you reach the next corner — not this turn. Then count backwards. If you need to be down to two squares a turn in three moves, you can afford at most one more turn of acceleration.

## How Dotrace adapts it

Dotrace keeps the constraint and drops the grid. Instead of marking discrete points on graph paper, you place control dots anywhere on the circuit and the ball follows a smooth curve through them — a Catmull-Rom spline — still respecting inertia: the faster it travels, the wider it has to turn.

Each dot you place counts as one move, and every circuit has a par , the number of moves a clean line should take. Beating par is the equivalent of the paper game's "fewest turns" goal.

The trade-off is deliberate: the smooth version is easier to pick up and reads better on a phone, at the cost of the crisp integer arithmetic that makes the paper original a favourite of maths teachers. If you want the exact original, graph paper is still the best implementation.

## Frequently asked questions

### Who invented the Racetrack game?

Its exact origin is unclear — it circulated among students and engineers through the 1960s. It became widely known when Martin Gardner described it in his Mathematical Games column in Scientific American in January 1973.

### What are the rules in one sentence?

Move your car by its previous velocity, adjusted by at most one square horizontally and one vertically, without crossing the edge of the track — first to the finish line wins.

### Can you play Racetrack alone?

Yes. Solo, the game becomes a puzzle: complete the circuit in as few turns as possible. That is the form Dotrace uses, with a par for each circuit.

### What happens if you crash?

In the most common version, the car returns to the last point on the track, its velocity resets to zero, and the player misses a turn. Some groups eliminate the player instead — agree before you start.

### What is vector racing?

Another name for Racetrack. Your move each turn is a vector — last turn's velocity adjusted by at most one square on each axis — which is exactly where the name comes from.

### How is Dotrace different from the paper game?

Dotrace replaces the integer grid with a smooth spline: you place dots freely and the ball curves through them. Inertia still governs how sharply it can turn, but the movement is continuous rather than square by square.

## Play Dotrace

Handcrafted circuits, a par on every one, and no account to create. Free in the browser, or in the app.

Play in the browser
Get the app

Related guides: the history of Snake ·
blackball rules

Free, no account, works offline. Dotrace is part of Casoual Games , a one-person studio.
More guides and rules for the other games.

---

# How to win at 2048 — the corner strategy, explained

Source: https://2048.casoual.games/strategy
Game: 2048 — https://2048.casoual.games/
Language: en

The short version. Pick one corner and never let your largest tile leave it. Use only the two directions that push toward that corner, plus a third when you must, and never the fourth . Keep the row along that edge sorted from biggest to smallest, so a single merge cascades down the whole row. That one discipline takes most players from 512 to 2048.

## The rules, precisely

A 4×4 grid. Every swipe slides all tiles as far as they go, and two equal tiles that collide merge into their sum. After each move that changed something, one new tile appears on a random empty square: a 2 nine times out of ten, a 4 once in ten .

You lose when the grid is full and no two neighbours are equal — no move changes anything. You win when a 2048 tile appears, and you can carry on afterwards if you want to go further.

Two consequences worth noticing straight away. First, the board fills up whether or not your move accomplished anything, so a wasted move costs you a square . Second, since almost every new tile is a 2, the board is mostly made of small tiles you have to shepherd — which is why space, not score, is the resource you are really managing.

## Why the corner

A large tile is only useful when something equal to it turns up. A 1024 can merge with exactly one thing: another 1024. Until then it sits there occupying a square, and it is the most expensive piece of furniture on the board.

If that tile wanders, it splits the grid into regions and cuts your usable space. Park it in a corner and it blocks nothing: it sits against two walls, out of the traffic, waiting.

1024
512
256
128

4
16
32
64

2
8

2

The shape to aim for: biggest in the corner, top row descending, small tiles kept below.

## The ordered row

The corner alone is not enough. What wins games is the top row sorted in descending order , as above: 1024, 512, 256, 128.

The reason is mechanical. When a second 128 finally arrives and merges, you get 256 — which now sits next to the existing 256, so those merge into 512, which meets the 512, which meets the 1024. One merge collapses the entire row. An unsorted row gives you one merge and nothing else.

So the real goal of every move is not to make a big tile. It is to keep that row in order while feeding it from below.

### Which directions to use

Say you have chosen the top-left corner. Then:

- Left and Up are your working moves. They push everything toward your corner and keep the top row packed.

- Down is the emergency move, when neither of the other two changes anything.

- Right is the move you do not play.

The move that loses the game
Swiping away from your corner slides the whole top row off the edge — including your biggest tile. Your 1024 ends up in the middle of the board, your ordering is gone, and the position you spent two hundred moves building cannot be rebuilt. Almost every game lost above 512 is lost on that single swipe, usually played on autopilot when the board looks stuck.

When Left and Up both do nothing, play Down, then immediately Left. Do not reach for the fourth direction.

## Feed from the bottom

With the top row locked, the game becomes a small logistics problem in the three rows below: merge the little tiles into something worth promoting, then push it up.

Two habits carry most of the improvement:

- Keep the top row full. A gap in it is an invitation for a new 2 to land there, and a 2 stuck between your 512 and your 256 is genuinely hard to remove.

- Merge low before you merge high. Clearing 2s and 4s buys space; making another 256 you have nowhere to put costs it.

The rhythm ends up being: several quick Left–Up moves to consolidate the bottom, then one that promotes a tile into the row.

## How far can you actually go?

What each milestone costs
Tile Merges needed In practice

512 ~255 Reachable without a plan

1024 ~511 Needs the corner held

2048 ~1023 Needs the row ordered too

4096 ~2047 Serious, and slow

131072 ~65535 The theoretical ceiling on 4×4

131072 is the largest tile a 4×4 grid can hold: reaching it needs all sixteen squares filled with a perfect descending chain, and the last 4 to appear exactly where it is needed. It has been done. It is not a goal.

If you only change one thing
Choose your corner before your first swipe and hold it for the entire game. Not "mostly" — every move. Players who do this and nothing else typically add one whole tile level to their best score.

## Frequently asked questions

### How do you play 2048?

Swipe to slide every tile on the 4×4 grid; two equal tiles that collide merge into their sum, and each move spawns a new tile — a 2 nine times out of ten, a 4 otherwise. You win by building a 2048 tile, and lose when the grid is full with no merge left.

### What is a good score in 2048?

Reaching 512 needs no plan; 1024 means you held a corner; 2048 means you also kept the top row ordered. Anything from 4096 up is expert play — the theoretical ceiling on a 4×4 grid is the 131072 tile.

### What is the best strategy for 2048?

Keep your largest tile in one fixed corner, use only the two directions that push toward it, and keep the row along that edge sorted from largest to smallest. That way a single merge cascades through the whole row instead of stopping after one step.

### Why do I keep losing around 512?

Almost always because the big tile moved. Swiping away from your corner slides the top row off the edge and scatters the ordering you built. When your two working directions do nothing, play the third — never the one facing away from your corner.

### Does 2048 involve luck?

Some. New tiles appear at random, and a 4 landing in the wrong square can cost you a position. But the game is mostly skill: the corner discipline works regardless of where tiles appear, which is why strong players reach 2048 consistently rather than occasionally.

### What is the highest possible tile in 2048?

131072, on a 4×4 grid. It requires all sixteen squares to hold a perfect descending chain of powers of two, with the final tile appearing exactly where it is needed.

### Can you keep playing after reaching 2048?

Yes. The game announces the win and lets you continue on the same board, which is how players go on to 4096 and beyond.

### Is a new tile always a 2?

No — it is a 2 about nine times out of ten and a 4 the rest of the time. That occasional 4 is what makes exact planning impossible and forces you to keep spare space rather than optimise every move.

## Play 2048

Free in your browser, no account, and it works offline once loaded.

Play now
Get the app

Related guides: word connect games ·
how to solve nonograms ·
sliding block puzzles

2048 is part of Casoual Games , a one-person studio. The original 2048 was created by Gabriele Cirulli in 2014.
More guides and rules for the other games.

---

# Blackball rules — English 8-ball pool, two shots and free ball

Source: https://pool.casoual.games/rules.html
Game: Pool — https://pool.casoual.games/
Language: en

In short. Blackball — also called English pool or eightball pool — is played with seven reds, seven yellows and a black. Pot a group to claim it, clear all seven, then pot the black to win. A foul hands your opponent two shots rather than ball in hand, and often a free ball . The governing body is the WEPF (World Eightball Pool Federation). American 8-ball, run by the WPA (World Pool-Billiard Association), uses solids and stripes, ball in hand, and called pockets.

Most confusion about pool rules comes from mixing the two codes. They share a name and a black ball, and almost nothing else about how a foul is punished. Below is blackball as this game plays it, followed by the comparison.

## The table and the balls

Fifteen object balls: seven reds, seven yellows, and the black — no numbers, no solids and stripes. Plus the white cue ball.

They are racked in a triangle with the black on the centre spot of the third row, and a red and a yellow in opposite back corners. The rack alternates colours as evenly as the triangle allows.

## Choosing your colour

The table starts open : neither player owns a colour. The first ball legally potted after the break sets it — pot a red and reds are yours for the rest of the frame.

If you pot one of each on the same shot, the table stays open and it is your opponent's turn. Potting the black while the table is open loses the frame outright.

## Taking your shot

Once colours are decided, a legal shot means the cue ball must strike one of your balls first. Pot one of yours and you carry on; miss and the turn passes.

You do not have to call your pocket. Anything of your colour that drops counts, including balls potted by accident — which is one of the real differences with the American game.

### Fouls, and the two shots

A foul is any of the following:

- Potting the cue ball — the scratch , or in-off .

- Hitting no ball at all.

- Hitting one of your opponent's balls first.

- Potting one of your opponent's balls.

The penalty is two shots , carried by your opponent. They may miss the first without losing the table, which turns an unpromising position into a chance to play safe and then attack. Two shots do not accumulate: fouling twice in a row still leaves your opponent with two, not four.

Free ball
If the foul leaves the incoming player snookered — unable to hit any of their own balls in a straight line — they get a free ball: for that shot, any ball on the table counts as theirs to hit first. They keep their two shots. It is the single most valuable thing you can hand an opponent, and the reason a safety that leaves them tangled is usually worth more than a low-percentage pot.

## Winning, and the four ways to lose on the black

Clear your seven, then pot the black. That is the whole win condition — no called pocket, no nominated cushion.

You lose the frame immediately if you

- pot the black before clearing your own colour;

- pot the black and the cue ball on the same shot;

- pot the black together with one of your opponent's balls;

- commit any foul on the shot that pots the black.

That last one catches people out. Being on the black is not a safe place to be careless: a scratch that would cost two shots at any other moment costs the frame here.

## Blackball versus American 8-ball

Both are called "8-ball" in ordinary speech, which is why rule arguments start. Here is where they actually part company.

The differences that change how you play

Blackball (WEPF) American 8-ball (WPA)

Balls Reds and yellows, unnumbered Solids 1–7, stripes 9–15

Table Smaller, 6 ft or 7 ft, tight pockets 7 ft to 9 ft, wider pockets

Foul penalty Two shots to the opponent Ball in hand, anywhere on the table

Snookered after a foul Free ball No such concept — ball in hand covers it

Calling pockets No Yes, every pot must be called

Accidental pot Counts, you continue Not called, so the turn ends

Black on the break Usually re-rack Re-spot or re-rack, at the shooter's option

The practical consequence is that ball in hand punishes a foul far more harshly than two shots do . In the American game a single mistake often ends the frame, so safety play dominates. In blackball a foul is survivable, and the free ball rule rewards leaving your opponent tangled rather than simply far away.

## Frequently asked questions

### What is the difference between blackball and American 8-ball?

Blackball uses unnumbered reds and yellows, punishes a foul with two shots and a possible free ball, and does not require you to call your pocket. American 8-ball uses numbered solids and stripes, gives ball in hand for a foul, and requires every pot to be called.

### Do you have to call your pocket in English pool?

No. In blackball any ball of your colour that drops counts, including one potted by accident, and you carry on. Calling pockets is an American 8-ball rule.

### What is a free ball in pool?

When a foul leaves the incoming player unable to hit any of their own balls in a straight line, they are awarded a free ball: for that one shot, any ball on the table may be struck first. They keep the two shots the foul earned them.

### Do two shots add up if I foul twice?

No. Two shots is a maximum, not a running total. Fouling again while your opponent already holds two shots leaves them with two.

### What happens if you pot the black too early?

You lose the frame immediately. The same applies if you pot the black along with the cue ball, along with one of your opponent's balls, or while committing any other foul.

### What happens if you pot the white ball in blackball?

It is a foul — the scratch, or in-off: your opponent gets two shots. If it happens on the shot that pots the black, you lose the frame outright.

### Which rules does this game use?

Blackball, following the WEPF code: two shots after a foul, free ball when snookered, no called pockets, and loss of frame on a foul involving the black.

## Play a frame

Against a bot that plays a real safety game, or against a friend online with a room code. Free, no account.

Play in the browser
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Related guides: les règles de la belote coinchée ·
Racetrack, the paper racing game

Free, no account, works offline. Pool is part of Casoual Games , a one-person studio.
More guides and rules for the other games.

---

# Word connect games — how the crossword grid works

Source: https://wordy.casoual.games/word-games.html
Game: Wordy — https://wordy.casoual.games/
Language: en

In short. In a swipe-to-spell game you are given a small set of letters — usually six or seven — and a crossword grid with every slot empty. Trace a word with your finger and it fills its slot. The letters are always the same for a board; the puzzle is finding which words the grid is asking for , and the grid, not the letter wheel, is what carries the difficulty.

## Why the grid does the work

A set of seven letters typically yields dozens of valid words. If the game simply asked for all of them, it would be a vocabulary test with a long tail of obscure entries — and an unsatisfying one, because you would never know when you were finished.

The crossword grid solves that. It tells you exactly how many words are wanted and how long each one is, so the task becomes bounded and readable: seven slots, one of them five letters crossing a four. You always know how far you have to go.

It also produces the format’s best moment. Filling a long word writes letters into every slot that crosses it, and three other answers become visible at once — the small cascade that makes the genre feel generous rather than punishing.

## What makes a good letter set

- Enough vowels. Two or three in a set of seven. Fewer and the board is a wall; more and everything becomes an anagram of everything else.

- One long anchor word. Most sets are built backwards from a word using every letter, which guarantees the board is solvable and gives the player a target worth hunting.

- Common letters, uncommon combinations. The pleasure comes from rearranging familiar letters, not from knowing rare ones. A board that hinges on Q or X is a trivia question.

This game precomputes its boards rather than generating them live, in English and French, so every grid has been checked to be completable with the letters given.

## Getting unstuck

- Work the crossing letters. A filled square in an empty slot is the strongest clue on the board — far more useful than staring at the letter wheel again.

- Say the letters aloud in a different order. Recognition is largely phonetic; rearranging the set physically or verbally breaks the visual grouping your eye has settled on.

- Try prefixes and suffixes systematically. RE-, UN-, -ED, -ER, -ING. Checking whether the remaining letters form a stem is faster than free association.

- Start with the shortest slot. Three-letter words are quick to guess and each one places letters into the longer words that cross it.

## Where the format came from

The swipe input arrived with touchscreens — tracing a path through adjacent letters is natural with a thumb and impossible with a keyboard. Early games kept it as a novelty on top of a word-search grid.

What made the genre stick was pairing that input with a crossword rather than a list. The list version has no shape and no end; the crossword gives a board that is legibly finished, which is what turns a word game into something you play one more round of.

## Frequently asked questions

### What are swipe-to-spell word games called?

The genre is usually called word connect: a small fixed letter set traced with a finger, feeding a crossword grid. The same games are also described as word-cross or swipe word puzzles.

### What games are like Wordscapes?

Any word-connect game — a ring of letters plus a crossword grid to fill. Wordscapes made the format famous; Wordy is a free browser version of the same idea, in English and French, with no account.

### How do I get unstuck on a word puzzle?

Use the crossing letters rather than the letter wheel: a filled square inside an empty slot narrows the possibilities far more than rearranging the set again. Then try common prefixes and suffixes systematically — RE-, UN-, -ED, -ING.

### Are the boards always solvable?

In a well-built game, yes. Boards are generally constructed backwards from a word that uses every letter, which guarantees the whole grid can be completed with the set you are given.

### Why is the crossword grid better than a word list?

Because it bounds the task. The grid states how many words are wanted and how long each is, so you always know how far you have to go — and filling a long word reveals letters in every slot that crosses it.

## Play Wordy

Chill word puzzles in English and French. Free, no account, works offline.

Play now
Get the app

Related guides: how to solve nonograms · how to win at 2048

Free, no account, works offline. Part of Casoual Games , a one-person studio.
More guides and rules for the other games.

---

# Règles de la belote coinchée — enchères, atout, points

Source: https://belote.casoual.games/regles.html
Game: Belote — https://belote.casoual.games/
Language: fr

En bref. La coinche se joue à quatre, en deux équipes, avec 32 cartes. Avant de jouer, les joueurs enchérissent : le preneur promet un nombre de points, de 80 à 160, avec une couleur d'atout. On joue ensuite 8 plis. Une donne vaut 162 points — 152 dans les cartes et 10 pour le dernier pli. Si le preneur atteint son contrat, il marque ; s'il lui manque un seul point, il tombe à zéro et la défense empoche tout.

La coinche — aussi appelée belote contrée — est la variante enchérie de la belote. Là où la belote classique retourne une carte pour désigner l'atout, la coinche laisse les joueurs se disputer le contrat aux enchères — c'est ce qui la rend plus tendue, et bien plus intéressante à quatre.

## Le but du jeu

La coinche se joue à quatre, en deux équipes. Toi et ton partenaire, assis en face de toi, contre les deux autres.

Chacun reçoit 8 cartes. On joue 8 plis : tout le monde pose une carte, et la plus forte ramasse le tas. Chaque carte ramassée vaut des points.

La première équipe à atteindre le total fixé — 501, 701 ou 1000 selon la partie — gagne. Ça prend cinq ou six donnes, une dizaine de minutes.

## Les enchères et le contrat

Avant de jouer, on parle. Annoncer, c'est promettre : mon équipe fera au moins tant de points, avec telle couleur comme atout.

Les annonces vont de 80 à 160 , de dix en dix, et chacune doit dépasser la précédente. Tu peux passer et reparler à ton tour suivant : passer ne t'élimine pas.

Le capot , c'est la grosse annonce : 250, la promesse de faire les huit plis et de ne rien laisser aux adversaires.

Après trois passes d'affilée , la dernière annonce devient le contrat, et son auteur devient le preneur. Les deux autres forment la défense. Si les quatre joueurs passent d'entrée, on ramasse et on redonne.

### Coincher et surcoincher

Coincher, c'est dire au preneur : tu n'y arriveras pas . Les plis et le contrat comptent alors double . S'il est sûr de lui, il surcoinche — et tout compte quadruple . C'est le grand frisson du jeu, et la façon la plus rapide de perdre une partie qu'on croyait gagnée.

Une seule chose échappe à la multiplication : les 20 points de la belote, qui restent 20 quoi qu'il arrive.

## L'atout et la force des cartes

L'atout, c'est la couleur annoncée par le preneur. Le plus petit atout bat n'importe quelle carte d'une autre couleur.

Et voilà le point qui déroute tout le monde quand on débute : les cartes n'ont ni la même force ni la même valeur à l'atout et ailleurs . Il n'y a pas de logique à chercher, seulement deux listes à connaître.

### À l'atout

7 < 8 < Dame < Roi < 10 < As < 9 < Valet
Le Valet est la carte la plus forte du jeu, le 9 vient juste derrière.

Valeur des cartes à l'atout — 62 points en tout
Carte Rang Points

Valet le plus fort 20

9 2 e 14

As 3 e 11

10 4 e 10

Roi 5 e 4

Dame 6 e 3

8 7 e 0

7 le plus faible 0

### Partout ailleurs

7 < 8 < 9 < Valet < Dame < Roi < 10 < As
Hors atout, le Valet et le 9 ne valent plus rien.

Valeur des cartes hors atout — 30 points par couleur
Carte Rang Points

As le plus fort 11

10 2 e 10

Roi 3 e 4

Dame 4 e 3

Valet 5 e 2

9 6 e 0

8 7 e 0

7 le plus faible 0

À retenir : à l'atout, le Valet et le 9 passent devant tout. Ailleurs, ce sont le 10 et l'As qui commandent.

### La belote et le rebelote

Si tu as le Roi et la Dame d'atout , ton équipe gagne 20 points, automatiquement, dès que tu joues la première des deux cartes. On annonce « belote » sur la première, « rebelote » sur la seconde.

Ta belote ne peut pas être perdue — ne garde donc jamais ton Roi d'atout pour la « protéger ». Les 20 points sont à toi dès que la première des deux cartes tombe, quoi qu'il advienne du pli.

## Ce que tu as le droit de jouer

Celui qui entame joue ce qu'il veut. Ensuite, dans l'ordre :

- Fournis la couleur demandée si tu en as.

- Si c'est l'atout qui est demandé , monte au-dessus du plus fort atout déjà posé — dès que tu le peux.

- Si tu n'as pas la couleur demandée , tu dois couper. Sauf si ton partenaire est déjà maître du pli : là, tu défausses ce que tu veux.

- Si tu coupes après un adversaire qui a déjà coupé , tu dois monter au-dessus — si tu le peux.

Deux règles qui surprennent, et que ce jeu applique à la lettre
Pas d'obligation de sous-couper. Si tu dois couper mais ne peux pas monter au-dessus de la coupe adverse, tu as le droit de défausser une carte ordinaire plutôt que de gâcher un petit atout.

Quand l'atout est demandé, on monte toujours — même si ton partenaire tient le pli. L'exception « partenaire maître » ne vaut que pour la règle 3, jamais pour la règle 2.

Ce ne sont pas des approximations : c'est la lecture littérale des règles, et elle s'applique exactement pareil aux quatre joueurs.

## Comment compter les points ?

Une donne vaut 162 points : 152 dans les cartes, plus 10 pour le dernier pli — le dix de der .

Le preneur additionne tout ce que son camp a ramassé, plus 20 s'il a la belote. S'il atteint son contrat, il marque ses points réalisés plus la valeur du contrat , et la défense garde les siens.

S'il lui manque un seul point, il est dedans : zéro pour lui, et la défense empoche 162 plus la valeur du contrat, plus 20 si c'est elle qui a la belote. Annoncer haut est un vrai risque.

### Un exemple chiffré

Contrat de 110 à cœur . Le preneur réalise 124 points : il tient son contrat. Il marque 234 (124 + 110), la défense marque 38 .

S'il n'avait fait que 96 , il chutait de 14 points seulement : il marquait 0 , et la défense 272 (162 + 110). Quatorze points d'écart valent 272 points au tableau — c'est toute la tension du jeu.

Coinché, les plis et le contrat comptent double, et seul le camp gagnant marque. Surcoinché, quadruple. Les 20 de la belote ne sont jamais multipliés.

### La fin de la partie

La première équipe à atteindre le total fixé gagne. Si les deux équipes le dépassent sur la même donne, c'est le plus haut total qui l'emporte ; à égalité parfaite, on joue une donne de plus.

## Coinche ou belote classique ?

Les deux se jouent avec les mêmes 32 cartes, les mêmes ordres et les mêmes valeurs. Une seule chose change : la façon de désigner l'atout .

À la belote classique , on retourne une carte au milieu de la table. Sa couleur sera l'atout si quelqu'un la prend — sinon on fait un second tour où chacun peut choisir une autre couleur. Pas d'enchères, pas de contrat chiffré, pas de coinche : on prend, on joue, on compte.

À la coinche , on annonce un nombre de points et on s'engage dessus. C'est plus long à apprendre et nettement plus tactique — l'enchère elle-même devient un moyen d'informer son partenaire.

Si tu débutes, commence par la classique une ou deux parties, le temps que les deux ordres de cartes rentrent. Le reste s'apprend en jouant.

## Questions fréquentes

### Quelle est la carte la plus forte à la belote ?

Le Valet d'atout, suivi du 9 d'atout. Hors atout, c'est l'As qui domine, devant le 10.

### Combien de points y a-t-il dans une donne ?

162 points : 152 répartis dans les cartes — 62 à l'atout et 30 dans chacune des trois autres couleurs — plus 10 points pour le dernier pli, le dix de der.

### Que veut dire « coincher » ?

C'est contrer l'annonce adverse : tu déclares que le preneur n'atteindra pas son contrat. Tout compte alors double. S'il maintient son annonce, il surcoinche et tout compte quadruple.

### Est-ce qu'on est obligé de couper ?

Oui, si tu n'as pas la couleur demandée — sauf si ton partenaire est déjà maître du pli, auquel cas tu défausses librement. En revanche, tu n'es jamais obligé de sous-couper : si tu ne peux pas monter au-dessus d'une coupe adverse, tu peux défausser.

### La belote-rebelote peut-elle être perdue ?

Non. Les 20 points sont acquis dès que la première des deux cartes est jouée, même si le pli est ramassé par l'adversaire. Ils ne sont jamais doublés par une coinche.

### La coinche et la belote contrée, c'est pareil ?

Oui. « Coinche » et « belote contrée » désignent le même jeu : la variante de la belote où l'atout se décide aux enchères et où l'on peut contrer — coincher — l'annonce adverse. Le nom varie selon les régions.

### Quelle est la différence entre la belote et la coinche ?

Les cartes, les ordres et les valeurs sont identiques. À la belote classique, l'atout est désigné par une carte retournée ; à la coinche, il est déterminé par des enchères où le preneur s'engage sur un nombre de points.

## Jouer une partie

Coinche ou belote classique, contre trois bots. Un mode coach grise les cartes que tu n'as pas le droit de jouer — impossible de te tromper le temps que les règles rentrent.

Jouer dans le navigateur
Télécharger l'app

À lire aussi : les règles du blackball (billard anglais)

Gratuit, sans compte, sans connexion nécessaire. La belote fait partie de Casoual Games , un petit studio indépendant.
Les guides des autres jeux sont recensés sur le site principal.

---

# Pipe puzzles — connecting a route by sliding, not rotating

Source: https://roll.casoual.games/pipe-puzzles.html
Game: Roll — https://roll.casoual.games/
Language: en

In short. A pipe puzzle asks you to form an unbroken path from an entry to an exit using straight and elbow segments. Two families exist. In the rotation kind, every piece stays where it is and you turn it until the route lines up. In the sliding kind, orientations are fixed and you move the pieces themselves through a board with one free square — which makes it a sliding block puzzle wearing a plumber’s hat, and much harder.

## Two puzzles with the same picture

The distinction matters more than it looks, because the two versions test opposite things.

In a rotation puzzle, every piece is independent: turning one never disturbs another. You can work on the top-left corner, be certain it is right, and never revisit it. The difficulty is reading — seeing which route the pieces can form.

In a sliding puzzle, nothing is independent. Moving a piece toward where you need it requires displacing whatever sits in between, and with a single empty square the pieces circulate slowly, like cars in a full car park. The difficulty is sequencing — and it is the same problem as the 15 puzzle, which is why it is genuinely hard rather than merely fiddly.

## The route is not the plan

The instinct is to picture the finished pipe and then move pieces toward it. On a sliding board that fails, because the route you want may not be reachable from where the pieces currently are.

The productive habit is the opposite: work backwards from the exit . Ask which piece must occupy the last square, then which one feeds it, and check at each step whether that piece can actually get there given the free square. A plan that is beautiful and unreachable costs more than an ugly one that works.

## Why some boards resist

Sliding puzzles have a parity property. On a 15-puzzle board, exactly half of all arrangements can be reached from any given start — the other half are unreachable no matter how long you push, which is precisely the trick Sam Loyd exploited in 1880 when he offered a prize for an impossible arrangement.

The practical consequence: if a board is well built, every level is solvable by construction, and a position that feels impossible is simply one you have shuffled into a bad corner of the reachable space. That is a reason to restart rather than to keep pushing.

## Getting better

- Finish one end and leave it alone. Lock the segments nearest the entry first; the free square then has less territory to cross.

- Move the empty square, not the pieces. Experienced players plan the route of the gap — every move is really a decision about where the hole goes next.

- Count your moves against the par. A level rated for twelve moves that has taken you thirty means the route is wrong, not that you are slow.

- Restart without regret. The board has no hidden state and no randomness. A fresh start costs seconds and beats untangling.

This game is the sliding kind: elbows and straights whose orientation never changes, rated by the number of moves a clean solution takes.

## Frequently asked questions

### What is a pipe puzzle?

A puzzle where you form a continuous route from an entry to an exit using straight and elbow segments. In one family you rotate pieces in place; in the other their orientation is fixed and you slide them around the board.

### Why is the sliding version harder than the rotating one?

Because the moves interfere. Rotating a piece never disturbs its neighbours, so you can solve the board region by region. Sliding one requires displacing others, which makes it a sequencing problem — the same one as the 15 puzzle.

### How do I plan a route?

Backwards from the exit. Decide which piece must occupy the final square, then which feeds it, checking at each step that the piece can physically reach that square given where the empty space is.

### Are all boards solvable?

In a well-built game, yes — levels are generated from a solved position, so a solution always exists. A position that feels impossible is one you have shuffled into a bad state, which is why restarting usually beats persevering.

## Play Roll

Slide the wooden tiles, build the pipe, roll the ball home. Free, no account.

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Related guides: sliding block puzzles · polyominoes · how to solve nonograms

Free, no account, works offline. Part of Casoual Games , a one-person studio.
More guides and rules for the other games.

---

# Sliding block puzzles — from Rush Hour to colour gates

Source: https://jam.casoual.games/sliding-block-puzzles.html
Game: Jam — https://jam.casoual.games/
Language: en

In short. A sliding block puzzle gives you pieces that move only by sliding — never lifting, never rotating — inside a frame too small for comfort. The difficulty is not the goal but the order : freeing one piece usually means putting three others in your way first. Rush Hour, published in the 1990s, is the version most people know; the colour-gate variant adds a second constraint by giving each block its own exit.

## What makes them hard

Nothing is hidden. You can see the whole board, there is no randomness, and every legal move is obvious. And yet a well-made board of a dozen pieces will stop a competent adult for twenty minutes.

The reason is that the moves are not independent . In most puzzles you can work on one part while leaving the rest alone. Here, the only way to free a piece is to move others into positions that block something else. Progress and regress look identical while you are making them.

This is not an impression. Deciding whether a sliding block configuration can be solved is PSPACE-complete — the class of problems that are hard for computers too, not merely tedious. Brute force does not rescue you here the way it does in chess endgames.

## A short history

The ancestor is the 15 puzzle, which swept America in 1880 — fifteen numbered tiles in a sixteen-square frame. Sam Loyd claimed credit and famously offered a prize for solving an arrangement that was mathematically impossible , which did the puzzle no harm at all.

Dad’s Puzzler followed in 1909, replacing numbered tiles with rectangles of different sizes — the shape the genre still uses. Then Nob Yoshigahara built Rush Hour in the 1980s, adding the idea that pieces slide only along their own axis, and that one specific piece has to reach the exit.

## Colour gates

The modern variant — popularised by mobile hits such as Color Block Jam — changes the goal. Instead of one piece escaping, every piece has to leave — each through the gate matching its colour.

That inverts how you plan. In Rush Hour you clear a path for a single target and everything else is an obstacle. Here every block is both cargo and obstacle, and the order you release them is the whole puzzle: send the wrong one out first and you have sealed the route for two others.

## How to read a jammed board

- Work backwards from the gates. Ask which piece must leave last — it is usually the one furthest from its own colour — and plan around it rather than around the piece that looks easiest.

- Find the piece nothing can move past. On most stuck boards there is exactly one, and every solution begins by dealing with it.

- Count the empty squares. A puzzle with one free square is a sequence, not a choice; with three or four, you have room to shuffle and the difficulty lies elsewhere.

- Undo early. Because progress and regress look alike, twenty moves down a wrong branch feels exactly like twenty moves of progress. Restart sooner than feels reasonable.

This game builds its boards by working the solution backwards from a solved position, which is why every level is guaranteed solvable and why its rating reflects the number of pieces actually involved rather than a guess at difficulty.

## Frequently asked questions

### What is a sliding block puzzle?

A puzzle in which pieces move only by sliding within a frame — they cannot be lifted out or rotated. The goal is to bring one piece, or every piece, to a target position. The 15 puzzle and Rush Hour are the best-known examples.

### Why are sliding block puzzles so difficult?

Because the moves interfere with each other: freeing one piece requires putting others in the way. Formally, deciding whether such a configuration can be solved is PSPACE-complete, which means it is genuinely hard for computers as well as for people.

### What is the difference from Rush Hour?

In Rush Hour a single target piece must reach one exit and everything else is an obstacle. In the colour-gate variant every piece must leave through the gate matching its own colour, so the order in which you release them becomes the puzzle.

### How do I get unstuck?

Work backwards from the exits rather than forwards from the easiest move, and identify the one piece that nothing can pass. If twenty moves have not opened anything, restart — on this kind of board a wrong branch feels exactly like progress.

### Is this the same kind of puzzle as Color Block Jam?

Yes — the same colour-gate mechanic: every block leaves through the gate matching its colour, and the order you release them is the puzzle. Jam is a free browser version of the format.

## Play Jam

A thousand boards, from four open walls to six-colour gridlocks. Free, no account.

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Related guides: polyominoes · pipe puzzles · how to solve nonograms

Free, no account, works offline. Part of Casoual Games , a one-person studio.
More guides and rules for the other games.

---

# Polyominoes — the shapes behind every block-fitting puzzle

Source: https://woodfit.casoual.games/polyominoes.html
Game: Woodfit — https://woodfit.casoual.games/
Language: en

In short. A polyomino is a shape made of unit squares joined edge to edge. Four squares give the tetrominoes — the seven Tetris pieces. Five give the twelve pentominoes , the classic puzzle set. Fitting a set of them into a fixed outline is the entire genre of block-fitting games, and it is a hard problem: the general case is NP-complete.

## How many are there?

The count grows fast, and no formula is known for it — the numbers below come from exhaustive computer enumeration, counting shapes as identical when one is a rotation or reflection of another.

Free polyominoes by number of squares
Squares Name How many

1 monomino 1

2 domino 1

3 tromino 2

4 tetromino 5

5 pentomino 12

6 hexomino 35

7 heptomino 108

8 octomino 369

The five tetrominoes become the familiar seven of Tetris because that game treats mirror images as different pieces — S and Z, J and L are reflections that cannot be rotated into each other on a flat screen.

## The twelve pentominoes

The pentominoes are the set the genre is built on, and they carry letter names for their shapes: F, I, L, N, P, T, U, V, W, X, Y, Z. Together they cover exactly 60 squares, which is why the classic challenge is to tile a 6×10, 5×12, 4×15 or 3×20 rectangle with all twelve.

The 6×10 rectangle has 2 339 distinct solutions. The 3×20 has just 2 . That collapse — same pieces, same area, a thousandfold difference in how forgiving the frame is — is the clearest illustration of what makes one board of a fitting game trivial and another cruel.

## Why fitting is hard

Deciding whether a set of polyominoes tiles a given region is NP-complete . There is no clever rule that reads a board and tells you the answer; past a certain size, the honest method is to try, backtrack, and try again.

When rotation is not allowed, the problem changes character rather than getting simpler. Each piece has exactly one orientation, so the search is smaller — but you lose the usual escape of turning an awkward piece to make it fit, and a hole of the right area may have no solution at all.

## The parity trick

One tool does let you rule out impossible puzzles without searching. Colour the target region like a chessboard, then count.

Some pieces always cover the same number of dark and light squares whatever their position; others always cover an unequal split. Add up what your set must cover and compare it with what the region actually has. If the totals cannot match, no arrangement exists — and you have proved it in thirty seconds instead of exhausting the search.

It is the same argument that shows a chessboard with two opposite corners removed cannot be covered by dominoes: the two missing squares share a colour, so 30 of one and 32 of the other can never be paired.

## Reading a fitting puzzle

- Place the awkward pieces first. Long straights and crosses have the fewest positions that work; the small compact ones fit almost anywhere and can wait.

- Start at the corners and edges. They constrain the most and give you certainty early.

- Watch for the single orphan square. A gap of one square that nothing can reach means the arrangement is already dead — restart rather than continue.

## Frequently asked questions

### What is a polyomino?

A shape formed by joining unit squares edge to edge. A domino is two squares, a tetromino four — the Tetris pieces — and a pentomino five. There are twelve distinct pentominoes.

### How many pentominoes are there?

Twelve, counting rotations and reflections of the same shape as one piece. They are named after the letters they resemble: F, I, L, N, P, T, U, V, W, X, Y and Z, and together they cover exactly 60 squares.

### Why can I not fit the pieces even though the area is right?

Matching area is necessary but not sufficient. A colouring argument often proves it outright: shade the region like a chessboard and count what each piece must cover — if the totals cannot balance, no arrangement exists at all.

### Is fitting polyominoes into a shape a hard problem?

Yes, formally. Deciding whether a set of polyominoes tiles a given region is NP-complete, so there is no general shortcut — beyond small boards the reliable method is systematic trial and backtracking.

### What changes when pieces cannot be rotated?

Each piece has a single orientation, which makes the search space smaller but the puzzle less forgiving: you cannot turn an awkward shape to rescue a placement, so a hole of the correct area may simply have no solution.

### Why does Tetris have seven pieces if there are only five tetrominoes?

Because Tetris counts mirror images as different pieces: S and Z, and J and L, are reflections that cannot be rotated into each other on a flat screen. Five free tetrominoes become seven one-sided ones.

## Play Woodfit

Fit every piece into the carved shape. Endless boards, free, no account.

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Related guides: sliding block puzzles · how to solve nonograms · pipe puzzles

Free, no account, works offline. Part of Casoual Games , a one-person studio.
More guides and rules for the other games.

---

# How to solve a nonogram — the overlap rule

Source: https://nono.casoual.games/how-to-solve-nonograms.html
Game: Nono — https://nono.casoual.games/
Language: en

In short. Each number is the length of an unbroken run of filled squares in that row or column, and the numbers appear in the order the runs appear. Two runs are always separated by at least one empty square. The fastest way in is the overlap rule : in a line of length n , a run of length b always covers the middle 2b − n squares, wherever it sits. Mark those, and the grid starts to unfold.

## What the numbers actually say

A nonogram — also called picross, a griddler, hanjie, or japanese crossword — is a grid where a hidden picture is described entirely by numbers written along its top and left edges.

Read a line labelled 4 2 . It says: somewhere along this line there is a run of exactly four filled squares, then later a run of exactly two, in that order, with at least one empty square between them. It does not say where. That is the whole puzzle.

Two consequences worth internalising early. First, a line labelled 0 is entirely empty — and that is real information, not a blank. Second, the minimum room a line needs is the sum of its numbers plus one gap between each pair: 4 2 needs 4 + 1 + 2 = 7 squares at the very least. If the line is only eight long, there is barely any slack — and slack is what you are always measuring.

## The overlap rule opens almost every grid

This is the single technique worth learning first, and it does most of the work.

Take a line of 10 squares labelled 8 . You do not know where the run of eight starts, but you can test the extremes. Pushed hard left it covers squares 1–8. Pushed hard right it covers 3–10. Whatever the truth, squares 3 to 8 are filled in both cases — so they are filled, full stop.

leftmost ████████··
rightmost ··████████
certain ··██████·· ← six squares proved, without knowing the answer
A run of 8 in a line of 10 overlaps itself by 2×8 − 10 = 6 squares.

The arithmetic generalises: a run of length b in a line of length n guarantees 2b − n squares in the middle. If that number is zero or less, the run tells you nothing yet — which is exactly why big numbers are your friends and you should always start with the fullest lines on the board.

The same reasoning works with several runs: compute the leftmost possible arrangement of all of them, then the rightmost, and keep whatever agrees.

## Crosses carry half the reasoning

Beginners fill squares and leave the rest blank. That throws away half of what they have worked out, because an empty square you have proved empty is worth exactly as much as a filled one — and the next deduction usually depends on it.

Mark them. A crossed square is a wall, and walls are what turn a vague line into a short one. A line of 10 with a cross at square 6 is really two independent lines of 5 and 4, each far easier to reason about than the original.

## Work from the edges

Edges give free certainty, because a run at the border has nowhere to slide.

- If the first square of a line is filled and the line starts with 3 , then squares 1, 2 and 3 are filled and square 4 is empty. No ambiguity at all.

- If the first square is crossed, the whole line shifts by one and you can redo the overlap arithmetic on a shorter line.

- A filled square adjacent to a cross behaves like an edge — which is why marking crosses keeps paying you back.

## Know when a line is finished

When the filled squares in a line already account for every number, everything else in that line is empty — cross the whole remainder at once. It feels like bookkeeping, but each of those crosses is a wall for the crossing lines, and that is usually where the next deduction comes from.

The reverse check is just as useful: if the empty squares already leave exactly enough room for the numbers, the remaining squares must all be filled.

## You should never have to guess

This is the line between a good nonogram and a bad one, and it is worth being blunt about.

A properly built puzzle can be solved by pure deduction : at every stage, some line has something new to prove, and you can reach the finished picture without ever trying a square to see what happens. A puzzle that stalls — where nothing anywhere is provable and the only way forward is to pick a square and hope — is not hard, it is broken. It has usually got there by having more than one valid solution.

So if you are stuck, the answer is almost never to gamble. It is that some line still has a deduction in it you have not read. Sweep the fullest rows and columns again, and pay particular attention to lines you have already partly solved: those are the ones whose walls have moved since you last looked.

## Getting faster

- Start with the biggest numbers. The overlap rule pays proportionally to run length.

- Re-read a line whenever a crossing line changes it. Most missed deductions are old lines with new walls.

- Cross as you go. It is not tidying, it is reasoning.

- Count before you fill. On a tight line, one mental subtraction beats three corrections.

- Do not solve the picture. Guessing the subject then filling squares to match is how mistakes get in — the numbers are the only evidence.

## Where to practise

Nono is a free nonogram game you can play in a browser, on phone or desktop, with no download and no account. Boards run from a gentle 5×5 up to 15×15, and every single one has been checked by a solver before shipping: if it cannot be cracked by pure deduction, it does not appear in the game. Solve a grid and it colours itself in to reveal the picture.

## Frequently asked questions

### What do the numbers on a nonogram mean?

Each number is the length of an unbroken run of filled squares in that row or column, listed in the order the runs appear. Consecutive runs are separated by at least one empty square. A line labelled 0 is entirely empty.

### What is the overlap rule?

In a line of length n, a run of length b always covers the middle 2b − n squares no matter where it sits. Comparing the leftmost and rightmost possible positions and keeping what they share proves squares without knowing the final answer.

### Is picross the same as a nonogram?

Yes. Picross is Nintendo's name for the same puzzle; griddler and hanjie are other names for it. The rules and solving techniques are identical.

### Do you ever have to guess in a nonogram?

No. A properly built nonogram has exactly one solution and can be reached by pure deduction. If a grid can only be advanced by guessing, it is faulty — usually because it admits more than one valid picture. Being stuck means a deduction has been missed, not that a gamble is required.

### Why mark empty squares with crosses?

A square proved empty is as informative as one proved filled. Crosses act as walls that split a long line into shorter, easier ones, and most subsequent deductions depend on them.

Play Nono
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More puzzle guides: polyominoes ·
sliding block puzzles ·
pipe puzzles

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