Hashi (Bridges)

Hashi — short for Hashiwokakero, and known in English as Bridges — is played on a grid of circled numbers called islands, and the goal is to connect every island with horizontal or vertical bridges so each island has exactly its number of bridges, at most two bridges join any pair, no bridges cross, and all islands form one connected network. Your task is to connect every island with bridges so that the whole archipelago becomes one connected network.

How many bridges does each island need?

The number on each island tells you exactly how many bridges must touch it. Bridges run only horizontally or vertically, never diagonally; you may lay at most two bridges between any pair of islands; and bridges are not allowed to cross one another or pass over an island. Finally, when every island has its required number of bridges, they must all join into a single connected group — you cannot leave two separate little networks.

The Hashi rules at a glance

Why is the solution always unique?

Those few rules are enough to force a unique answer. Because a bridge between two islands either exists (once or twice) or it doesn’t, every island number is a hard counting constraint, and the no-crossing and all-connected rules tie the whole grid together. Every board on this page is generated and checked to have exactly one solution reachable by logic alone, so you never need to guess.

To solve Hashi, start with the islands whose numbers force their bridges — a corner 4 or an edge 6 must use a double in every direction — then settle each forced bridge before the next, tracking how many bridges every island still needs and never guessing. A few reliable moves crack almost every board:

Which islands force their bridges first?

• Maxed-out islands. An island whose number equals twice the directions it can reach must use a double bridge in every direction. A corner 4 (two directions) and an edge 6 (three directions) are the classic forced openings — draw all their doubles immediately.
• Almost-maxed islands. A 3 in a corner, or a 5 on an edge, must place at least one bridge in every direction it can reach, because it cannot meet its number otherwise.
• The only neighbour. If an island can reach just one other island, the bridges between them are forced — up to the smaller number, or two.

How do connection and crossing rules narrow the grid?

• No premature islands. Never seal a small group of islands into its own closed network while others remain; the final layout must be one connected whole, so a move that isolates a finished cluster is illegal.
• Use crossings. Once a bridge is placed, any bridge that would cross it becomes impossible; ruling those out narrows other islands’ options.

The winning habit is to settle every forced bridge first — the corners, edges and single-neighbour islands — and let each one reduce the choices around it. Track how many bridges each island still needs, and never guess: a proper Hashi always has a provable next bridge.

Start from a corner island marked 4: it can only bridge right and down, so reaching four forces a double bridge in both directions — and those four bridges immediately constrain their far ends, growing the network outward from the certainties.

The forced corner

A single corner shows the rhythm. Suppose the top-left corner holds an island marked 4. A corner island can only send bridges in two directions — right and down — and with a maximum of two bridges each, the only way to reach four is a double bridge in both directions. Draw them in without hesitation.

How each bridge constrains its neighbours

Those four bridges immediately constrain their far ends. Say the island two squares to the right was a 3: it now already has two bridges from the corner, so it needs just one more, and only from its remaining open directions. If it can reach only one other island, that last bridge is forced too.

Each forced bridge trims another island’s options, and the network grows outward from the certainties. Keep an eye on the connected rule as you finish: when the final bridges go in, every island should already be linked into one continuous map — never a guess required.

This page offers Hashi at two sizes: a 7×7 grid with 7 islands for a brisk, friendly solve, and a denser 9×9 grid with 12 islands for a longer challenge. The grid size matters less than how many islands are packed in and how their numbers interact.

• The 7×7 board is ideal for learning the forced-corner and edge patterns; the network is small enough to keep entirely in view.
• The 9×9 board adds more islands and longer chains, so the all-connected rule does more work and you plan further ahead before committing a bridge.

Tap New for a fresh layout at either size, or play the shared Daily to take on the same archipelago as everyone else that day.

Hashi is best known by three names: its Japanese title Hashiwokakero (roughly, “build bridges”), the plain English Bridges, and occasionally Chopsticks — all the same puzzle, so any tip carries across.

Hashi is a connection puzzle — its charm is wiring everything into one network — which puts it close to the path-and-loop puzzles in this collection. If you like building a single connected structure, try Slitherlink, where you draw one closed loop along the grid, or Masyu, where a single loop must thread through pearls. All three reward thinking about how local choices keep, or break, one connected whole.

The core Hashi vocabulary is short: an island is a circled number, a bridge is a straight horizontal or vertical link, a double bridge is the two-bridge maximum between a pair, the network is the finished web that must connect every island, and a crossing is the illegal case of one bridge passing over another. A few words come up whenever Hashi is discussed:

• Island — a circled number; the number is how many bridge-ends it must have.
• Bridge — a straight horizontal or vertical link between two islands.
• Double bridge — two parallel bridges between the same pair (the maximum allowed).
• Network — the finished web of bridges, which must connect every island into one piece.
• Crossing — an illegal situation where one bridge would pass over another; never allowed.

You don’t need the jargon to play — just tap between two islands — but it makes guides easier to follow.

Most Hashi tangles come from a few habits: guessing a bridge, forgetting the all-connected rule, putting a third bridge between one pair, ignoring crossings, or closing off a cluster before the rest are linked. Most Hashi tangles trace back to a few habits:

• Guessing a bridge. An unjustified bridge can satisfy one island while quietly making another impossible. Find the forced move instead.
• Forgetting the connected rule. A grid where every number is satisfied but the islands form two separate clusters is not solved — plan so everything ends up linked.
• Over-bridging a pair. No more than two bridges may join the same two islands; it is easy to add a third while chasing a big number.
• Ignoring crossings. Once a bridge is down, the lines it blocks are off the table — use that to narrow other islands.
• Closing a cluster early. Completing a self-contained group before the rest are connected forces a restart.

Beyond the forced corners, recurring shapes speed up every solve: two lone 1s facing each other cannot bridge, a 2 between two lone 1s sends one bridge each way, lines of high numbers force their doubles, near-self-contained clusters force a bridge out, and a late island with one open neighbour hands you its last bridge. A handful of recurring patterns speed up every solve:

Patterns with lone 1s and 2s

• Two lone 1s facing each other with no other neighbours cannot bridge each other — a single bridge would satisfy both yet leave them cut off from the rest, breaking the connected rule. The bridges must go elsewhere.
• A 2 between two lone 1s must send one bridge each way, because a double to either side would over-fill that 1.

Patterns with high numbers and sub-networks

• High numbers in a line. When several large islands sit in a row, the doubles between them are often forced simply to reach their totals, zipping the line together in one move.
• Sub-network watch. Keep an eye on any cluster that is nearly self-contained; the rule that everything must end up connected often forces a bridge out of it to the rest of the grid.
• Last-bridge counting. Near the end, an island needing one more bridge with a single open neighbour hands you that bridge for free.

Recognising these shapes turns a daunting grid of numbers into a sequence of quick, certain moves — and keeps you mindful of the rule that matters most at the finish: the whole map must be one connected network.

Hashi is worth playing because it is pure deduction with no arithmetic and no luck — you read an island, lay the bridges it forces, and watch the network spread across the board until everything clicks into one connected whole. There is no arithmetic to grind through and no luck involved — just clean deduction and the quiet pleasure of clicking everything into one connected whole. A 7×7 board is a tidy five-minute solve; a 9×9 is a longer, more absorbing puzzle for when you want to settle in.

Like the rest of this collection it is fair by design: every board has a single answer you can reach by reasoning, so progress always feels earned rather than lucky. Playing the shared Daily gives you the same archipelago as everyone else and a small streak to keep. And because Hashi trains you to think about connectivity and knock-on consequences — how one bridge shapes the whole map — it pairs naturally with the loop and path puzzles here. Once you enjoy wiring islands together, Slitherlink and Masyu are an easy next step.

Hashi is a modern classic from the Japanese publisher Nikoli, where it first appeared around 1990 as Hashiwokakero — literally an instruction to “build bridges” — before spreading worldwide in English as Bridges. It joined Sudoku, Slitherlink and the rest of Nikoli’s line-up of pencil puzzles that travelled the world.

As it spread to English-speaking solvers it was published simply as Bridges (and here and there as Chopsticks). The appeal never changed: a scattering of numbered islands, a couple of crisp rules, and a single connected answer you can reach by pure logic — no arithmetic, no guessing, just careful counting and a feel for keeping the whole map in one piece.