Safecracker

About the game

Safecracker is a game of deduction. Behind the door is a four-digit code, and you have twelve chances to find it. Your current guess is the column of digits on the right; every guess you have already tried stays on the screen to its left, so the whole story of the safe is always in front of you.

No digit appears twice in the code, and the game will not let you waste a try on a guess that repeats one: an X sits above such a guess, and an OK appears once all four digits are different. After each attempt, a row of up to four dots answers you. A dark dot means a digit is correct and in the right place. A light dot means a digit is in the code but somewhere else. Fewer than four dots means some of your digits are not in the code at all, and no dots means none of them are.

Open the safe within twelve guesses and you win; use them all without finding it and the game is over. Either way, one more press starts a fresh safe with a new code.

Playing it here

The program is assembled from the author's unchanged source, with the speed and colours of his own release on itch.io. The game is silent, as the author notes, and works on a phone too: tap the screen to bring up the CHIP-8 keypad.

Controls

Digits wrap around, so going down from 0 gives 9 and going up from 9 gives 0.

Tips

• Start with four new digits. Two first guesses that share no digits tell you quickly which digits are in the code.
• Count both kinds of dots. The total number of dots tells you how many of your digits belong to the code, whatever their place.
• Move one digit at a time. Changing a single position between guesses makes it easy to see what each change did.
• Look back. Every earlier guess stays on screen, so check a new idea against all of them before you press F.