Sokoban#Selected official releases

{{Infobox video game series

| title = Sokoban

| platforms = {{Unbulleted list|

Various

}}

| image = Official Sokoban website banner.png

| caption = Sokoban official fan kit banner

| genre = Puzzle

| creator = Hiroyuki Imabayashi

| first release version = Sokoban (Thinking Rabbit)

| first release date = 1982

| latest release version = The Sokoban (Unbalance)

| latest release date = 2021

}}

{{nihongo|Sokoban|倉庫番|Sōko-ban|lead=no|extra={{lit|warehouse keeper}}{{cite book |author1=Yoshio Murase |author2=Hitoshi Matsubara |author3=Yuzuru Hiraga |title=Automatic Making of Sokoban Problems |editor1=Norman Foo |editor2=Randy Goebel |date=1996 |publisher=Springer Science & Business Media |isbn=978-3-540-61532-3 |page=592 |url=https://books.google.com/books?id=j2QrFVEd2GUC&dq=sokoban+meaning+warehouse&pg=PA592 |language=en}}}} is a puzzle video game in which the player pushes boxes around in a warehouse, trying to get them to storage locations. The game was designed in 1981 by Hiroyuki Imabayashi and first published in Japan in 1982.

Gameplay

File:Sokoban_ani.gif

The warehouse is a grid composed of floor squares and impassable wall squares. Some floor squares contain a box and some are marked as storage locations. The number of boxes equals the number of storage locations.

The player, often represented as a worker character, can move one square at a time horizontally or vertically onto empty floor squares, but cannot pass through walls or boxes.

To move a box, the player walks up to it and pushes it to an empty square directly beyond the box. Boxes cannot be pushed to squares with walls or other boxes, and they cannot be pulled.

The puzzle is solved when all boxes are on storage locations.

Progressing through the game requires careful planning and precise maneuvering.{{cite magazine |date=December 1983 |script-title=ja:倉庫番 |quote=考えずにスイスイ荷物を動かすと, 最後は必ず行き詰まる。倉庫番で最も重要なのは、最初の一手、この一手を実行する前に、先の先まで読み切ることが大切。 |language=ja |trans-quote=If you push boxes around carelessly without thinking ahead, you will inevitably end up at a dead end. In Sokoban, the most critical move is the very first one — before making it, you must think several moves ahead and visualize all possible outcomes. |magazine=MICOMGAMES |volume=1 |issue=1 |page=38}} A single mistake, such as pushing a box into a corner or obstructing the path of others, can render the puzzle unsolvable, forcing the player to backtrack or restart. Anticipating the consequences of each push and considering the overall layout of the puzzle are crucial to avoid deadlocks and complete the puzzle successfully.{{cite conference |author1=Jean-Noël Demaret |author2=François Van Lishout |author3=Pascal Gribomont |title=Hierarchical Planning and Learning for Automatic Solving of Sokoban Problems |date=2008 |url=https://orbi.uliege.be/bitstream/2268/5895/1/bnaic2008.pdf |pages=1,2 |quote=a bad move can lead in Sokoban to a deadlock, a situation in which the solution game state is not reachable anymore.}}

History

Sokoban was created in 1981 by Hiroyuki Imabayashi.{{cite magazine |date=December 1983 |script-title=ja:考えるウサギはパソコンの |language=ja |trans-title=The Rabbit Who Thinks About Computers |magazine={{ill|ログイン (雑誌)|ja}} |pages=136-139 |url=https://archive.org/details/login-magazine-dec-1983-thinking-rabbit/page/5/mode/2up}}{{cite web |title=Thinking Rabbit - 1983 Developer Interview |url=https://shmuplations.com/thinkingrabbit/}}{{cite web |title=My conversation with Mr Hiroyuki Imabayashi |url=https://sokoboxes.com/articles/my-conversation-with-mr-hiroyuki}} The first commercial game was published for the NEC PC-8801 in December 1982 by his company, Thinking Rabbit, based in Takarazuka, Japan. Ports and new titles for various platforms appeared in subsequent years. In 1988, Spectrum HoloByte published Sokoban in the U.S. for the IBM PC, Commodore 64, and Apple II as Soko-Ban.{{cite conference |author1=Austin Barr |author2=Calvin Chung |author3=Aaron Williams |title=Block Dude Puzzles are NP-Hard (and the Rugs Really Tie the Reductions Together) |page=1 |year=2021 |conference=CCCG (2021) |url=https://www.cs.ucf.edu/courses/cot6410/Spring2022/SampleTopics/Games/CLAIMED_JesseChehal_BlackDudePuzzles.pdf#page=2}} In 2001, the Japanese software company Falcon acquired the trademarks for Sokoban and Thinking Rabbit. Since then, Falcon has continued to develop and license official Sokoban games.

Versions

Since its debut in 1982, Sokoban has been released on various platforms, primarily in Japan but also in other regions. Most titles are independent without a continuous narrative or unified series, though a few are direct sequels to a specific earlier release—for example, Sokoban 2 (1984) follows Sokoban (1982), and Soko-ban Revenge (1991) is a sequel to Soko-ban Perfect (1989). The following table lists a selection of official Sokoban titles.{{cite web |url=https://sokoban.jp/history.html |title=倉庫番の歴史 |website=Thinking Rabbit |access-date=2025-06-02 |language=ja}}

class="wikitable" style="white-space:nowrap;"

!Year

!Title

!Country

!Platform

!Publisher

1982

|{{nihongo|Sokoban|倉庫番}}{{cite magazine |date=December 1983 |script-title=ja:倉庫番 |quote=一度やりだしたらなかなかやめられない。 |language=ja |trans-quote=Once you start playing, it’s hard to stop. |magazine=MICOMGAMES |volume=1 |issue=1 |page=38}}{{cite magazine |date=October 1983 |script-title=ja:倉庫番 |magazine=パソコンゲームランキングブック |page=28 |url=https://web.archive.org/web/20250531231153/https://retoge-mag.websa.jp/archives/15}}: scored the game 94 points out of 100.

|Japan

|NEC PC-8801

|Thinking Rabbit

1983

|{{nihongo|Sokoban [Extra Edition]|倉庫番[番外編]}}{{cite magazine |date=August 1983 |script-title=ja:倉庫番[番外編] |quote=今回はこのゲームを開発した THINKING RABBIT さんにお願いして, 市販品とは別に10の倉庫をつくってもらいましたので |language=ja |trans-quote=This time, we asked THINKING RABBIT, who developed this game, to build 10 warehouses separately from commercial products |magazine={{ill|PCマガジン|ja}} |pages=52–56}}

|Japan

|NEC PC-8801

|{{ill|PCマガジン|ja|lt=PC Magazine}}

1984

|{{nihongo|Sokoban 2|倉庫番2}}{{cite magazine |date=July 1985 |script-title=ja:倉庫番2 |quote=パズルソフトのベストセラー倉庫番の新たな50面と迷路エディタがついた倉庫番 2 。 |language=ja |trans-quote=Sokoban 2, the sequel to the bestselling puzzle game Sokoban, comes with 50 new levels and a maze editor. |magazine={{ill|ログイン (雑誌)|ja}} |page=76 |url=https://archive.org/details/logi-n-july-1985/LOGiN%20-%20July%201985/page/n77/mode/2up}}

|Japan

|NEC PC-8801

|Thinking Rabbit

1986

|{{nihongo

涙の倉庫番スペシャル|Namida no Sokoban Special

}

|Japan

|Famicom Disk System

|ASCII

|1988

|Soko-Ban{{cite magazine |date=April 1988 |title=The Role of Computers |magazine=Dragon |issue=132 |pages=84 |last1=Lesser |first1=Hartley |last2=Lesser |first2=Patricia |last3=Lesser |first3=Kirk}}: reviewers rated the game {{frac|4|1|2}} out of 5 stars.

|US

|IBM PC, XT, and AT

|Spectrum HoloByte

|1989

|{{nihongo|Soko-ban Perfect|倉庫番Perfect}}

|Japan

|NEC PC-9801

|Thinking Rabbit

|1990

|Boxyboy

|US

|TurboGrafx-16

|NEC

|1990

|Shove It! ...The Warehouse Game

|US

|Sega Genesis

|DreamWorks

|1991

|{{nihongo|Soko-ban Revenge|倉庫番Revenge}}

|Japan

|NEC PC-9801

|Thinking Rabbit

|2016

|{{nihongo|Sokoban Touch|倉庫番Touch}}

|Japan, US

|Android, iOS

|Thinking Rabbit

|2018

|{{nihongo|Sokoban Smart|倉庫番スマート}}

|Japan

|Windows

|Thinking Rabbit

|2019

|{{nihongo||みんなの倉庫番|Minna no Sokoban}}

|Japan

|Nintendo Switch, PlayStation 4

|{{ill|Unbalance|ja|UNBALANCE_(ゲーム会社)}}

|2021

|The Sokoban

|US

|Nintendo Switch, PlayStation 4

|Unbalance

Reception

By June 1984, the original Sokoban had sold 22,000 copies in Japan;{{cite magazine |date=June 1984 |script-title=ja:ソフトハウス訪問 |language=ja |trans-title=Visiting a Software House |magazine=POPCOM |page=131 |url=https://archive.org/details/popcom-198406/page/130/mode/2up}} by March 1985, it had reached 30,000 copies.{{cite magazine |date=March 1985 |script-title=ja:作者が語る自信のニューソフト |language=ja |trans-title=The creator presents their new software |magazine=POPCOM |page=29 |url=https://archive.org/details/popcom-198503/page/28/mode/2up}}

Sokoban was a hit in Japan, selling over 400,000 copies before being released in the United States.{{cite magazine |author=Lafe Low |magazine=inCider |title=News Line; Made in Japan |date=November 1988 |page=14 |url=https://archive.org/details/inCider_1988-11/page/n15/mode/2up}}

The 1988 American release, Soko-Ban, received a positive review from Computer Gaming World, which described the game as simple yet mentally challenging, and praised its addictive nature.{{cite magazine |last=Wagner |first=Roy |date=May 1988 |title=Puzzling Encounters |magazine=Computer Gaming World |issue=47 |pages=42–43 |url=https://web.archive.org/web/20250603043037/http://pdf.textfiles.com/zines/CGW/1988_05_issue47.pdf#page=42}}

Legacy

=Cultural impact=

An active fan community has produced thousands of custom puzzles,{{cite journal |author1=Petr Jarusek |author2=Radek Pelánek |year=2010 |title=Difficulty Rating of Sokoban Puzzle |journal=Frontiers in Artificial Intelligence and Applications |volume=222 |pages=140-150

|doi=10.3233/978-1-60750-675-1-140 |quote=There is a very large number of levels of the puzzle freely available on the Internet. These available levels span wide range of difﬁculty.

}} unofficial versions, and software tools, including puzzle editors, solvers, and solution optimizers.

=Derivatives=

Sokoban is considered the originator of a subgenre of puzzle games featuring box-pushing mechanics. These games are commonly referred to as "Sokoban-like" or "box-pushing" games".{{cite thesis |author=Robert Aubrey Hearn |title=Games, Puzzles, and Computation |degree=PhD |page=106 |publisher=Massachusetts Institute of Technology |year=2006 |url=https://erikdemaine.org/theses/bhearn.pdf#page=106}}

Alternative tilings: In the standard game, the mazes are laid out on a square grid. Several variants apply the rules of Sokoban to mazes laid out on other tilings. Hexoban uses regular hexagons, and Trioban uses equilateral triangles.
Multiple pushers: In the variant Multiban, the puzzle contains more than one pusher. In the game Sokoboxes Duo, strictly two pushers collaborate to solve the puzzle.
Designated storage locations: In Sokomind Plus, some boxes and target squares are uniquely numbered. In Block-o-Mania, the boxes have different colours, and the goal is to push them onto squares with matching colours.
Alternative game objectives: Several variants feature different objectives from the traditional Sokoban gameplay. For instance, in Interlock and Sokolor, the boxes have different colours, but the objective is to move them so that similarly coloured boxes are adjacent. In CyberBox, each level has a designated exit square, and the objective is to reach that exit by pushing boxes, potentially more than one simultaneously. In a variant called Beanstalk{{cite journal |author1=Ziwen Liu |author2=Yang Chao |title=The Non-Deterministic Constraint Logic and Its Applications in Computational Complexity |language=Chinese |journal=Computer Science and Application |volume=7 |pages=407–413 |publisher=Hans Publishers |year=2017 |url=https://web.archive.org/web/20250604194130/https://pdf.hanspub.org/csa20170500000_69174065.pdf |doi=10.12677/csa.2017.75049 |access-date=2025-06-04

}}, the objective is to push the elements of the level onto a target square in a fixed sequence.

Additional game elements: Push Crate, Sokonex, Xsok, Cyberbox and Block-o-Mania all add new elements to the basic puzzle. Examples include holes, teleports, moving blocks and one-way passages.
Character actions: In Pukoban, the character can pull boxes in addition to pushing them.
Reverse mode: Some Sokoban programs allow players to play a puzzle backward. This approach can help players better understand the puzzle structure and develop effective solving strategies. Starting with all boxes on storage locations, the player pulls the boxes to return to the initial puzzle state. Solutions found this way solve the standard puzzle when both the order and the direction of the moves are reversed.{{cite web |author=Frank Takes |title=Sokoban: Reversed Solving |year=2008 |url=https://liacs.leidenuniv.nl/~takesfw/pdf/sokoban.pdf}}

Computer science research

Sokoban has been studied using the theory of computational complexity. The computational problem of solving Sokoban puzzles was first shown to be NP-hard.{{cite journal |author1=Michael Fryers |author2=Michael Greene |title= Sokoban |journal=Eureka |issue=54 |year=1995 |pages=25–32

|url=https://www.archim.org.uk/eureka/archive/Eureka-54.pdf#page=28 |archive-url=https://web.archive.org/web/20240905040633/https://www.archim.org.uk/eureka/archive/Eureka-54.pdf#page=28 |archive-date=2024-09-05}}{{cite journal |author1=Dorit Dor |author1-link= Dorit Dor |author2=Uri Zwick |author2-link=Uri Zwick |title=SOKOBAN and other motion planning problems |journal=Computational Geometry |volume=13 |issue=4 |year=1999 |pages=215–228 |doi=10.1016/S0925-7721(99)00017-6 |doi-access=free}} Further work proved it is also PSPACE-complete.{{cite journal |author=Joseph C. Culberson |title=Sokoban is PSPACE-complete |journal=Technical Report TR 97-02, Dept. Of Computing Science, University of Alberta |year=1997 |url=http://cl-informatik.uibk.ac.at/teaching/ss07/alth/material/culberson97sokoban.pdf |archive-url=https://web.archive.org/web/20240528042859/http://cl-informatik.uibk.ac.at/teaching/ss07/alth/material/culberson97sokoban.pdf |archive-date=2024-05-28}}{{cite thesis |author=Robert Aubrey Hearn |title=Games, Puzzles, and Computation |degree=PhD |pages=98–100 |publisher=Massachusetts Institute of Technology |year=2006 |url=https://erikdemaine.org/theses/bhearn.pdf#page=98}}

Solving non-trivial Sokoban puzzles is difficult for computers because of the high branching factor (many legal pushes at each turn) and the large search depth (many pushes needed to reach a solution).{{cite journal |author1=Andreas Junghanns |author2=Jonathan Schaeffer |title=Sokoban: Improving the Search with Relevance Cuts |journal=Theoretical Computer Science |date=2001 |volume=252 |issue=1–2 |url=https://webdocs.cs.ualberta.ca/~jonathan/publications/ai_publications/tcs.pdf#page=5 |page=5 |doi=10.1016/S0304-3975(00)00080-3 |doi-access=free}}{{cite web |author=Yaron Shoham |title=FESS Draft |page=3 |year=2020 |url=https://festival-solver.site/wp-content/uploads/2020/08/FESS_draft.pdf#page=3}} Even small puzzles can require lengthy solutions.{{cite web |author1=David Holland |author2=Yaron Shoham |title=Theoretical analysis on Picokosmos 17 |url=http://membres.lycos.fr/nabokos/analysis.html |archive-url=https://web.archive.org/web/20160607071224/http://www.abelmartin.com/rj/sokobanJS/sokoban-jd.blogspot/sokoban_lessons/picokosmos17/analysis.htm |archive-date=2016-06-07}}

The Sokoban game provides a challenging testbed for developing and evaluating planning techniques.{{cite thesis |author=Timo Virkkala |title=Solving Sokoban |degree=MSc |page=1 |publisher=University of Helsinki |year=2011 |url=https://weetu.net/Timo-Virkkala-Solving-Sokoban-Masters-Thesis.pdf#page=5}} The first documented automated solver, Rolling Stone, was developed at the University of Alberta. It employed a conventional search algorithm enhanced with domain-specific techniques such as deadlock detection.{{cite thesis |author=Andreas Junghanns |title=Pushing the Limits: New Developments in Single-Agent Search |degree=PhD |publisher=University of Alberta |year=1999 |url=https://www.researchgate.net/publication/2305703 |doi=10.7939/R3W95103S |doi-access=free}}{{cite journal |author1=Andreas Junghanns |author2=Jonathan Schaeffer |title=Sokoban: Enhancing general single-agent search methods using domain knowledge |journal=Artificial Intelligence |volume=129 |issue=1–2 |year=2001 |pages=219–251 |doi=10.1016/S0004-3702(01)00109-6 |doi-access=free}} A later solver, Festival, introduced the FESS search algorithm and became the first automatic system to solve all 90 puzzles in the widely used XSokoban test suite.{{cite conference |author1=Yaron Shoham |author2=Jonathan Shaeffer |title=The FESS Algorithm: A Feature Based Approach to Single-Agent Search |date=2020 |url=https://ieee-cog.org/2020/papers/paper_44.pdf |conference=2020 IEEE Conference on Games (CoG) |location=Osaka, Japan |doi=10.1109/CoG47356.2020.9231929 |publisher=IEEE}}{{cite web |author=Yaron Shoham |title=FESS presentation at the CoG conference (17.5 minutes) |url=https://archive.org/details/fess-algorithm |website=archive.org |language=en |format=video |date=2020}} Despite these advances, even the most sophisticated solvers cannot solve many highly complex puzzles that humans can solve with time and effort, using their ability to plan ahead, recognize patterns, and reason about long-term consequences.{{cite journal |author1=Petr Jarusek |author2=Radek Pelánek

|year=2010 |title=Difficulty Rating of Sokoban Puzzle |journal=Frontiers in Artificial Intelligence and Applications

|volume=222 |pages=140-150 |doi=10.3233/978-1-60750-675-1-140

|quote=There exist small instances that can be quickly solved by computer (using a trivial brute force algorithm) but take humans hours to solve. At the same time, there are also instances of the puzzle, which humans can solve but which are beyond capabilities of [...] artificial intelligence solvers.}}{{cite web |url=https://archive.org/download/lets-logic-bots-statistics/lets-logic-bots-statistics-2024-oct-06.pdf |title=Let's Logic Bots Statistics |access-date=6 October 2024}}{{cite web |url=https://sokoban-solver-statistics.sourceforge.io/statistics/LargeTestSuite/ |title=Sokoban Solver Statistics - Large Test Suite |access-date=14 April 2024}}