Online logic game

Tower of London: move the balls in as few moves as possible

Also known as: Tower, ball puzzle, Tower of London test

Move the balls between three pegs until they match the target picture. A round lasts two minutes, puzzles come one after another, and the fewer extra moves you make, the more points you get. You can play 10 minutes a day without signing up.

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2 minutesper round
2–7 movespuzzles get longer
No sign-up10 minutes a day
Progress30-day chart

What it trains

Why play the Tower of London

The exercise puts your planning to work: before you pick up a ball, it pays to think through the whole chain of moves. The pegs have different heights and hold three, two and one ball, so the direct route often doesn’t work and you first have to make room.

In your account the trainer is called “Tower”. Once you sign up, your rounds are saved: you see how many puzzles you solved, how many with no extra moves and how long the puzzles got, and a 30-day chart shows how your score changes.

You start doing before you’ve thought about the orderExtra moves show up right away on the counter
You take a step and then have to redo everythingPlanning several moves ahead
You like puzzles where you think rather than rushPoints depend on the number of moves, not just speed
You want a puzzle that grows with youSolve with no extra moves and the next one is longer

Planning

Think through the chain of moves before you pick up the first ball.

Working memory

Keep track of where each ball will be two or three moves from now.

Inhibition

Resist the obvious move if it takes you away from the goal.

Checking your result

The move counter next to the minimum shows how precise your solution was.

Rules

How to play

Goal
The target picture is shown at the top, with your pegs below it. A hint tells you in how many moves the puzzle can be solved.
Pick up a ball
Tap a peg and its top ball lifts up. You can only take the top ball.
Put it down
Tap another peg and the ball lands on top. The pegs hold three, two and one ball; you can’t put a ball on a full peg.
Reset
If you get tangled up, press “Reset the balls”, and the puzzle starts over. The move counter isn’t reset.
Points and difficulty
Solve it in the minimum number of moves and the next puzzle is one move longer. Make three or more extra moves and it’s one move shorter. The longer the puzzle and the fewer extra moves, the more points you get.

Play online

Tower of London online

Tap a peg to pick up a ball and another peg to put it down. Without signing up you get 10 minutes of play a day.

Tower

Move the balls to match the target picture. You can only take the top ball. The fewer moves, the more points.

Free play left today without signing up: 10 min

Method

What the exercise is based on

The Tower of London was proposed by British neuropsychologist Tim Shallice in the early 1980s as a planning task. The classic version is the same as here: three balls of different colors and three pegs that hold three, two and one ball.

The puzzle is similar to the Tower of Hanoi, but there the disks differ in size and a larger one can’t go on a smaller one. If you like thinking several moves ahead, try 2048 Online.

2Two movesEvery round starts at this length

3–5Three to five movesThe order of moves starts to matter

6–7Six or seven movesThe longest puzzles in the trainer

Who it’s for

Which ages

Adults

A two-minute planning puzzle: you can take it calmly, since points depend on more than speed.

Kids

The trainer isn’t in the “Kids” collection. The rules are clear, but long puzzles take planning many moves ahead. Better for older children.

60+

The trainer isn’t in the “60+” collection. If you like calm puzzles, give it a try: each round starts with two-move puzzles, and they only get longer once you solve them with no extra moves.

Questions

Frequently asked questions

How many points does a puzzle give?

Solve it with no extra moves and you get three times as many points as the puzzle has moves: 12 points for a 4-move puzzle. Extra moves mean fewer points, but a solved puzzle always gives at least one.

What if I made extra moves?

The puzzle still counts. With one or two extra moves the next puzzle stays the same length; with three or more it gets one move shorter.

How is it different from the Tower of Hanoi?

In the Tower of Hanoi the disks differ in size, and a larger one can’t go on a smaller one. In the Tower of London the balls differ in color and the pegs differ in height: they hold three, two and one ball.

Do I need to sign up?

No, you can play 10 minutes a day right away. A free account lets you keep playing, save your results, track your progress and unlock the daily workout.

Does it work on a phone?

Yes, the trainer runs in the browser on phones, tablets and computers. There’s nothing to install.

Save your results and track your progress

Free sign-up: round history, a chart by skill and a daily workout of 5 exercises. No credit card needed.

All trainers

Tower of London: move the balls in as few moves as possible