Prove you’re a master code breaker with the vintage puzzle game Mastermind Online! Find the sequence by placing the coloured balls in the exact right position. The game will help you, but not too much! See a grey dot? That means you chose one of the colours in the sequence, but you’ve still got ways to go. A black dot means you matched the right colour with the right position, so you’re getting there. The fewer guesses you need, the higher your score!