• Drag from one colored endpoint to its matching endpoint.
• Pipes move only up, down, left, or right.
• Every ordinary square must contain exactly one pipe.
• A bridge holds two pipes. One travels horizontally and the other vertically.
• A pipe must go straight through a bridge. It cannot turn or end there.

Drag backward over your active pipe to shorten it. With a keyboard, use the arrow keys to move the focus square, Space to select an endpoint, and the arrow keys again to extend that pipe.