Jam Breaker

Jam Breaker is a sliding-block puzzle set in a car park. A 6 × 6 lot is packed with cars two spaces long and trucks three spaces long, and every vehicle can only roll along its own lane — the way it is facing, or backwards. Somewhere among them sits the red car, on the row that leads to the exit on the right-hand side. Clear its way and drive it out.

It looks simple, and the first moves usually are. The trouble is that every vehicle you push aside lands in front of something else, and the move that finally frees the red car is often one you have to set up from the far corner of the lot. Easy puzzles take around eight to twelve moves; hard ones need more than twenty, in exactly the right order.

Every puzzle is made by our server, which also works out the fewest moves it can possibly be solved in. That number is shown while you play. Solving the puzzle at all earns XP and coins; solving it in that many moves, without a hint, is a Perfect.

How to start a game

1. 1Open Jam Breaker on Alex Play Zone and press Start Puzzle; the clock starts when the car park opens.
2. 2Drag a car or truck along its lane and let go. It slides as far as it can and stops on the nearest space; on a computer, a vehicle you have clicked also moves with the arrow keys.
3. 3The counter shows your moves so far, next to the fewest possible.
4. 4Undo takes back your last move. Restart puts every vehicle back where it began and your move count back to zero — the clock keeps running.
5. 5Hint makes the next move of the shortest way out for you, from wherever the vehicles stand now.

The rules of Jam Breaker

The rules

• Vehicles move only along their own lane: a car lying across the lot slides left and right, one standing up and down slides up and down.
• A vehicle cannot pass through another, and nothing may leave the lot except the red car through the exit.
• Sliding a vehicle any distance in one go counts as one move.
• The puzzle is solved the moment the red car reaches the exit.

Perfect

• Every puzzle has a fewest number of moves, worked out by the server.
• Get the red car out in exactly that many moves, without a hint, for a Perfect — a quarter more XP and coins.
• Undo and Restart are allowed. Only the moves of your final way out are counted.

A new puzzle every two hours

• One new puzzle is made every two hours, and it is the same for every player.
• You get one go at each puzzle. Leave and come back whenever you like: your grid is kept and the clock only runs while the puzzle is open.
• When the next puzzle arrives, an unfinished one is closed and shows as abandoned in your Battle Log.

Rewards

• The faster you finish, the more XP and coins you earn.
• Up to 28 for an easy puzzle, 44 for a medium and 60 for a hard one — 35, 55 and 75 with a Perfect.
• Each hint takes 10% off the reward and rules out a Perfect.

How to play well

Work backwards from the exit

Look along the red car’s row and name every vehicle in its way. Then, for each of those, ask where it could go and what is stopping it. A chain of three or four such questions usually shows you the first real move — and it is often a truck at the edge of the lot that has nothing to do with the red car directly.

Trucks are the real puzzle

A truck standing upright in the red car’s row needs three free spaces in its column to get out of the way, and a column has only six. Find the side — up or down — that can be cleared, and plan everything around giving the truck that room.

Slide as far as you need, not as far as you can

Since a slide of any length is one move, it is tempting to push every vehicle to the end of its lane. But a car parked hard against a wall can block a whole row for the rest of the game. Leave space where the next vehicle will need it.

Solve first, then go for Perfect

If the fewest-moves target feels out of reach, simply get the red car out — a solve earns most of the reward. If you spot a shorter way along the way, Restart puts everything back and sets your move count to zero, while the clock keeps your time.

Remember: Work backwards: ask what blocks the red car, then what blocks that vehicle. The first move is often far from the red car.

Common mistakes

• Moving the vehicles closest to the red car first, when the blockage really starts further away.
• Pushing a car all the way to a wall out of habit and boxing in the next vehicle that needs to pass.
• Making the same move and its reverse again and again — if you are going round in circles, stop and trace what blocks what.
• Forgetting that Undo is free: a move you regret can be taken back without counting against you.

Questions and answers

How many moves does a puzzle take?

Easy puzzles take about eight to twelve moves, medium ones fourteen to twenty-one and hard ones twenty-three to thirty. The exact fewest number is shown on the board.

Does Undo count as a move?

No. Undo takes your last move back and the counter goes down by one. Restart sets it back to zero.

Can I still get a Perfect after a Restart?

Yes. Only the moves on your final way out count, so a fresh try after Restart can still be a Perfect — as long as you have not used a hint.

Is there always a way out?

Always. Every car park is made by the server together with its shortest way out, so you know it can be done.