There are lines with numbers in white spaces. At the end of each line, there is a number in a grey space. For each line, the sum the numbers in white spaces must be equal to the grey number. To win, you will have to cross exactly 6 white spaces. Each crossed white space won’t count for the grey numbers value. Take a pen and a timer (10 minutes for a 1-player game, 5 for a 2-player game). When you are ready to start, launch the timer. If you finish the game before the end of the timer, you win. If you have lost, look to one of the solutions. —description from the designer