First Sokoban program

From Sokoban Wiki

Jump to: navigation, search

The Sokoban game was invented in 1981 by Hiroyuki Imabayashi, Japan, and was first published by his software company, Thinking Rabbit, in December 1982 for the NEC PC-8801 computer. The game was distributed as cassette tape media.


Start of the game

Screenshot of the entry screen of the game:

The text roughly translates to:
** Sokoban **

You have started a part-time job in a large warehouse company.

Your job is to clear up 20 warehouse buildings.

You must organize the boxes in the buildings.

Because the boxes are large, you can only push them one at a time.

If you do a bad job the boxes will get stuck.
Hence, you have to be careful.

5 Key (Up)
1 Key (Left)
2 Key (Down)
3 Key (Right)

The boxes must be placed on the red dots.

Press the F1 key when the job is done, or if you want to start over again.

Press the Space key to start!

Program features

The game offers 20 levels to be played.

After a level has been solved it's necessary to press F1. This makes the program check whether the level has been solved, in which case the player can proceed to the next level.

If F1 is pressed when the level hasn't been solved, the player is given the choice between exiting the game and restarting the level.

The player has 5 attempts to solve the level, meaning it's possible to restart a level 4 times.

This first version of the program erroneously makes the dots representing the goal squares disappear when the player walks over them.


The first 10 levels are regular Sokoban levels.

Levels 11 to 20 contain some destructible walls.

These special walls look the same as the other not destructible walls.

However, the player can walk over these walls from specific sides and thereby destroy the walls.

This is level 15 in the original game:
image:First Sokoban Level 15 normal walls.png

This is the same level having the destroyable walls highlighted in blue and the direction they can be walked over indicated by small arrows:
image:First Sokoban Level 15 highlighted walls.png

The levels first become solvable after destroying these special walls.

The walls can only be destroyed when entering them from one specific side. However, in level 20 there is one exception.
Level 20 contains a destructible wall at the top right which can be entered from left and right:
image:First Sokoban Level 20 special wall.png

Later versions of Sokoban don't contain this special destructible wall type anymore.

Source code

The source code of this first Sokoban game was printed in the 1987 book "THE 倉庫番", pages 117-122.

The program was written in BASIC.

Game solved

After the last level has been solved (and F1 has been pressed so the game checks if the level is solved) the game prints "Congratulation": image:First Sokoban Game solved.png

Game texts

[Level failed]
Do your best or you’ll get fired!
Try again?(Y/N)

[Level complete]
The first warehouse is done!
Go to the next warehouse?(Y/N)

[Game over]
You’re now dismissed!
Start over?(Y/N)

[All levels complete]
The message is ”ウサギ(rabbit)”

Interview with Hiroyuki Imabayashi

You can read a 1983 interview with Hiroyuki Imabayashi on

Carlos Montiers Aguilera published his interesting 2020 Internet conversation about Sokoban with Hiroyuki Imabayashi at:

Play the game

Using a so-called emulator, the original program can run on newer computer systems. Here is a package that lets you install and play the original program on computers with the Microsoft Windows operating system:

Sokoban 1982 - The First Sokoban Program.

The package contains two versions of the program:

  • 1982 - The original 1982 Sokoban program.
  • 2022 - A bugfixed and enhanced version of the 1982 Sokoban program.
Personal tools