FourLock is a four-digit deduction duel: you hide a secret code, your opponent hides theirs, and you race to crack each other's first.
No board, no pieces — just two clues and a clock ticking down your attempts.
HOW TO PLAY
Pick four digits, 0–9, no repeats. Guess your opponent's code and read two numbers after every attempt:
• Positions — how many digits are in the exact right slot
• Numbers — how many exist elsewhere in the code
Up to 20 attempts. Fewer attempts wins; equal attempts is a draw.
THREE WAYS TO PLAY
• Pass & Play — two players, one device. Set your secret, hand off with a countdown so it stays private, then crack theirs.
• Online Match — share a room code and duel a friend on their own device, anywhere. Both boards open at once, so you're both guessing in real time.
• Play vs AI — three difficulty levels, Easy to Hard. Every match plays both directions so results are always comparable.
FAIR FROM THE START
Who sets the first secret is decided by an honest coin flip — never hardcoded to whoever played first.
YOUR DATA
Play as an anonymous guest or sign in with Google to keep your stats across devices. No ads, no third-party tracking, and your secret code is only ever stored while its round is active.
TRACK YOUR PROGRESS
Win/loss record, win percentage, average and best attempts, and win streaks — with full guess history for every match.
Simple to understand. Difficult to master.
Crack the code. Outsmart your opponent. Local, online or vs AI duels.