The Dual N-Back game field is a square separated to smaller squares with lines (like 3x3 cross-zero game field).

During the game the image is shown in one of the game squares.

Your task is to find a match of the current position of the image to the position shown one (or two) step earlier. If there was a match press the corresponding match key. Same thing for the colors. Just watch and try to remember the colors from the previous steps.