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The haunted vending machine

This JAVA applet is a software implementation of the Vending Machine puzzle, a mechanical puzzle by Oskar van Deventer, see photo below. The object is to insert the indicated amount of coins. However, the machine seems haunted and keeps rejecting your coins. Can you persuade the machine to accept your coins?

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Insert coins until the vending machine is completely full of coins (all switches turn red). All switches support one coin only. You have an unlimited supply of coins.


Use Start to start with the easiest challenge.
Use Previous to go to an easier challenge.
Use Next to go to a harder challenge.
Use Reset to restart the current challenge.
Use Drop-list to select a challenges.
Use Slider to adjust the animation speed.


Click the coin that you want to insert, or...
Press the number (1, 2, 3 etc) of the required coin.

Here is a photo of the original mechanical Vending Machine puzzle, designed and hand-crafted by Oskar.

concept & applet - © Oskar van Deventer 2002-04
hosted with permission from Oskar van Deventer
The haunted vending machine was inspired by the MB game Avalanche