Logic Masters Deutschland e.V.

Some rulesets, no matter how brilliant, often go unnoticed. In occasion of the Turn 5 of The Skunkworks League I decided it's time to shining a light on one such hidden gem: Recoil. This ruleset was introduced at the end of 2020, and until now, it only had a single published puzzle, created by a LMD user named SebastianSimon and still unrated. You can find that puzzle at this link. The name Recoil was suggested by the user Thomster and I decided to take it.

This puzzle is meant to be solved after solving the first introduction to the genre, published with ID 000MDT. You will find another harder puzzle with ID 000ME7.

Rules

Starting at the black diamond, draw a directed path through the centers of some cells in the grid. Path segments are drawn sequentially from cell to cell, such that the first path segment is drawn from the black diamond to an adjacent empty cell, the second segment is drawn from that cell to the next empty cell, and so on until the final segment is drawn and the path ends.

The path cannot branch or revisit a cell it has visited before.

Every time the path enters a new cell, a “recoiled cell” is placed in the first empty cell in the opposite direction. This recoiled cell may skip over gaps in the grid, other recoiled cells, or other path cells.

The path cannot enter a cell if its corresponding recoiled cell cannot be placed into the grid.

All cells of the grid must be visited by the path or contain a recoiled cell.

In the example below a simple Recoil puzzle is shown. All the recoiled cells are in grey. Please notice how the recoiled cells work for the last two steps of the path: r2c1 is the last recoiled cell of the entire puzzle because it's the nearest empty cell in the opposite direction of the last step.

SebastianSimon's puzzle also includes an animated GIF of a simple solved Recoil, which may help you better understand the solving process.

Special thanks to X_Sheep, for implementing a functional Recoil editor and player on Pzprxs, and to Nordy, for the invaluable help in writing the ruleset.

Have fun solving and please leave a comment after your solve!