How to play Crossline
A metro-map logic puzzle. Draw each line from one station to its twin until the whole board is a working network.
The three rules
- Connect matching stations. Each colored station has exactly one partner with the same color and symbol. Drag from one to the other to lay a line.
- Fill every cell. The puzzle is solved only when lines cover the entire grid — no empty cells left.
- Cross straight at interchanges. An interchange (the white circle with a plus) is where two lines must pass through, one horizontally and one vertically. Lines can't turn there, and lines can't cross anywhere else.
Controls
- Draw: drag from a station with your finger or mouse. Drag back over your own line to shorten it.
- Undo (Z), Restart (R) and Hint (H) are always one tap away.
- A hint reveals one complete line. You earn hints by clearing the daily puzzle and every 10th level.
Solving tips
Start at the edges and corners
A station in a corner has only two ways out. Lines hugging the edge of the board are usually forced, so lay those first.
Interchanges fix directions
Because two lines must go straight through, an interchange tells you the four cells around it all belong to lines. Work out which color takes the horizontal and which takes the vertical — often only one choice lets both reach their stations.
Look for cells nobody else can reach
If an empty pocket can only be filled by one nearby line, that line has to detour through it. Every cell must be filled, so long winding lines are normal.
When you're stuck
If every line is connected but the puzzle isn't solved, Crossline highlights the empty cells or the interchange that isn't crossed correctly. Pull a line back and try a longer route.
Daily puzzle
A new daily puzzle unlocks at midnight UTC and is the same for everyone in the world. Solve it to extend your streak, then share your time and hint count — the result never spoils the answer.