Mastermind, known in Brazil as Senha, is a deduction classic that pits two players against each other in a logic duel. One player takes on the role of codemaker, secretly selecting a four‑peg sequence from six colors (duplicates and empty slots are allowed). The other, the codebreaker, tries to uncover that combination in ten or fewer attempts. After each guess the codemaker provides two clues: a black peg means a correct color in the correct position; a white peg means a correct color in the wrong position. Using these hints, the codebreaker employs deductive reasoning to narrow down possibilities until the code is cracked or the attempts run out. The game includes a portable board, 108 code pegs in six colors, 30 key pegs in two clue colors, and a shield to hide the secret code. A typical round lasts about 20 minutes, making it perfect for quick sessions or as a warm‑up before a longer game. While the rules are simple, the over 2,000 possible codes ensure no two games feel the same, and the tension of trying to "break the code" in few moves keeps the experience thrilling. Suitable for ages 8 and up, it also appeals to adults who enjoy short mental challenges. With more than 55 million copies sold, Mastermind has become one of the world’s most popular strategy games, blending accessibility, replayability, and a dash of suspense that satisfies both beginners and seasoned deduction fans.