QUADLOCK: 1A2B Code Puzzle

One 1A2B guess can reveal clues to crack multiple codes. QUADLOCK turns the classic 1A2B number game, also known as Bulls and Cows, into a multi-lock logic puzzle. Instead of solving a single secret code, you will work on several safes at once. Enter one unique 4-digit guess and every locked safe responds. Read the clues, rule out impossible combinations, and crack every code before your queries run out. Easy to learn, satisfying to solve Each secret code contains four different digits. A means a digit is correct and in the right position. B means the digit is in the code but in the wrong position. A result of 2A1B, for example, means two digits are exactly right and one more digit belongs in a different place. Use each response to refine your next guess. Solve several number codes together Choose a 2-safe warm-up, take on the standard 4-safe challenge, or test your strategy against 8 safes. Every guess applies to all unsolved codes, so one carefully chosen number combination can help eliminate possibilities across the whole board. Compare the feedback from each safe and turn separate clues into a larger deduction. Linked rules change the puzzle Some challenges make every code share a digit. Others restrict the available digit pool or require every safe to start with a different digit. These linked rules create opportunities to reason across safes: a clue from one code may help you narrow down another. A final chance to keep going Crack any safe with your final query and earn one extra query. A last-second solve can give you the opening you need to continue working on the remaining codes. Follow every clue Review the feedback history for each safe and see how many possible codes remain. Use the candidate count to plan your next move, practice deduction, and improve your number-logic strategy one guess at a time. A lively pixel cipher agent reacts as you play. With quick number entry and clear A/B feedback, QUADLOCK is ready for a short brain teaser during a break, a commute, or whenever you want a focused logic challenge. Every new round generates a fresh set of codes, so the same strategy challenge can unfold in a different way each time. Start by testing which digits appear, then use later guesses to confirm their positions. Or choose a guess that separates several likely combinations at once. There is no single fixed route to every solution: compare the clues, eliminate possibilities, and find a deduction style that works for you. Looking for a 1A2B game, Bulls and Cows, a code breaker, a number puzzle, a deduction game, or a brain teaser? Put your logic to work, use every clue, and unlock every safe in QUADLOCK.