by Jakhob and wooferzfg

This puzzle is a variant of U-Bahn with empty cell clues, which originates from a series by KNT.

If you are unfamiliar with U-Bahn, here is a guide that covers the core logic.


Draw a loop network through the centers of some cells, which may branch or turn, but may not have any dead ends.

A clue outside the grid indicates in how many cells the corresponding behavior (i.e. turn, straight line, branch, cross, or unvisited) occurs in the row or column, irrespective of rotation.

5x5 Example Puzzle

Play the Example on Penpa+

Play the Example on SudokuPad

Puzzle Links

Play on Penpa+

Play on SudokuPad