Log Jam

Slide the logs to free the boat from the frozen river.

🤔 How to play

A little boat is stuck in a log jam on a frozen river. Clear a path, then slide the boat out through the gap in the right-hand bank.
Logs only slide along their own length: a log lying across goes left and right, and a log lying along the river goes up and down. Nothing can pass through anything else.
A move is one log sliding any distance in one direction. Each level shows the fewest moves it can be done in. Match it for a ★.
Stuck? Undo, start again, or ask for a hint: a solver works out the best next move from wherever you are.

Controls

Touch or mouse: drag a log along its line. Or tap a log, then tap an open square in its line to slide it there.
Keyboard: Tab or the arrow keys pick a log (it glows, and little arrows show which way it can go). The arrow keys along the log slide it one square at a time; hold to keep going. Z undoes, R restarts and H or 💡 shows a hint.

There are four groups of nine: warm-up, medium, hard and expert, from 2 moves up to 39. Every level was made and checked by computer, and there are no dead ends: any slide can be slid back. Nothing is saved: ticks for finished levels last only this visit.

What it practises

Planning several moves ahead and reasoning backwards from the goal ("what has to move before that log can move?"). Untangling a chain of dependencies like this is the same thinking used in programming, scheduling and proofs, and the fewest-moves target rewards finding the efficient route, not just any route.

Log Jam

Choose your skipper

Pick a puzzle

This game needs 3D graphics

🤔 How to play

Controls

What it practises