how to play roads
Roads (also known as Hashiwokakero, Bridges, or Hashi) is a logic puzzle on a 10x10 grid. The numbered circles are cities. Each number says how many roads connect to that city. Your job is to join every city into one network.
You shouldn't need to guess. Every board has exactly one solution that can be reached by applying the rules below.
the rules
Two cities can be joined by either a single road or a double road.
A city's number is how many roads meet it. A double road counts as two.
No road crosses another.
Every city has to be reachable from every other. You can't have two clusters that never connect.
Roads run across and down, never diagonally. A city can only reach the nearest city in each direction.
a worked example
Let's walk through solving a 5x5 board, one step at a time. The real puzzle is 10x10, but the logic is the same.
Nine cities and no roads yet. Each city tells you how many roads must connect to it.
The 4 in the top-left corner has only two neighbors: the 3 across the top and the 4 below it. Four roads over two directions means a double road to each.
That gives the 3 two of its three roads. Its only other direction is down the column, and one road there finishes both the 3 and the 1 it lands on.
That vertical road separates the 4 on the left edge from the 2 on the right. The 2 can only reach downwards, so both of its roads go down to the corner.
The 4 on the left edge has two roads from above and can't go right, so its last two run down to the bottom-left corner.
The bottom-left 4 has only two neighbors too, so it doubles both ways. Double roads connect to the 5 in the bottom row.
Same for the bottom-right 4: two roads already come down the right edge, so the other two connect to the 5.
The 5 needs one road and the 1 near the top is available. One vertical road connects them. All done!
controls
Tap on a city and drag towards a neighbor. This draws a road between the cities. Do it again for a double road. Tap the road to clear it.
If using a keyboard: arrow keys move between cities, shift with an arrow cycles roads in that direction. You can also use enter to select a city, then move to a neighbor and press enter again to connect them.
tips
- Look for doubles. A city whose number is double the count of its open neighbors must have a double road to every one of them. A 4 in a corner, a 6 on an edge, an 8 in the middle.
- Look for corners. A 3 in a corner must have at least one road in each direction. A 5 with three neighbors must have at least one each way, and a 7 with four.
- Don't make a loop. Two 1s facing each other are never connected, and neither are two 2s by a double road. They would be cut off from the rest of the network.