Inscrutable FourDC -Imprisonment-

Do you think solving puzzles is easy? That it’s only natural to find the answer?

"Inscrutable FourDC -Imprisonment-" is a game of extreme difficulty, where you must sharpen your mind for one purpose: deriving a single 4-Digit Code (4DC).

■ A System Built Purely for the Pursuit of Answers

No Time Limit

There is no clock to race against. Stay calm and focus on the problem for as long as you desire.

Five Attempts Only

You are allowed only five guesses per problem. Make each one count.

Progressive Hints

If you fail twice on the same problem, a hint will be provided for each subsequent mistake.

Forced Progression

A fifth incorrect answer will forcibly move you to the next problem. Even if you fail to solve a single riddle, you will still reach the ending.

Freedom of Choice

You can move to other problems at any time before submitting an answer. Sometimes, a change of pace is the best way to cool your head.

Provision of Tools

A calculator and notepad are provided within the game. Use them to your advantage.

Will you put your resources to the ultimate test?

■ Video Posting & Live Streaming Guidelines

You are welcome to stream or post videos of this game (both Full and Demo versions), including the ending. Monetization through official platform features (Ads, Super Chat, etc.) is also permitted. Please refer to our website for further details.

■ Sample Problem

Q1:

3 -> 1592

15 -> 3238

6 -> □□□□

Don't worry.

This is one of the easy ones.