The present invention relates to an operation method for executing games on mobile camera enabled terminal devices and to devices capable of executing the method. The method is based on hiding augmented reality messages in pictures by taking an image of an object, providing symbols; linking the symbols to the image, such that the symbols are not visible when displaying the image, and sending the image and the linked invisible symbols via a wireless connection as a first image to a mobile camera terminal device. The invention also provides a second component to re-visualize the hidden message by receiving the first image, taking a second image with a camera of the mobile camera terminal device, displaying the second image, comparing the first and second images to determine a matching measure, and visibly displaying the linked invisible symbols on the display, if the comparison fulfills at least one predetermined condition.