Turn on the light by solving the logical formula! You will see a circuit with AND, OR, NOT and XOR gates, as well as input switches A, B, C... Choose the right combination to make the output TRUE. The fewer switches you use, the more stars you'll get: ★ for a solution, ★★ for an almost optimal one, ★★★ for the optimal solution without hints.
Over 100 manually designed levels await you, with increasing difficulty. There's also a Daily Challenge with a unique puzzle generated each day. Hints, the ability to undo actions and an achievement tree are available to help you. No timer, no penalties — just a brain workout. The game is available in 7 languages.
How to play
To achieve the goal of lighting the bulb, switch the input buttons A, B, C... between 0 and 1. Use the available buttons: hint, ↶ undo, ↺ reset. The fewer times you change the settings, the more stars you'll earn.