["Beyond Tetris" is a new column from Tony "Tablesaw" Delgado about puzzle games that transcend mere abstract action and instead plunge deep into the heart of problem-solving. This first installment looks at one of the most persistent puzzle games, Soko-Ban.]

In 1982, puzzles about moving squares around weren't new. A hundred years previous, the world had been captivated by sliding squares around the 15 puzzle, and Rubik's Cube had just recently brought square-relocation into the third dimension. But the time was ripe for computers to revolutionize pushing of squares from their initial locations to other, different locations (preferably in a minimum number of moves).

Soko-Ban was published by Thinking Rabbit games in 1982, and was released to the West by Spectrum Holobyte in 1984. It featured a titular warehouseman pushing boxes around grid. And it was revolutionary. It moved mechanical puzzles into the virtual world, and established crate-pushing as one of the most fundamental videogame puzzles, a paradigm that continues to this day.

The Warehouse Revolution

Level 1 from the Spectrum Holobyte release of Soko-Ban

It seems odd that an avatar would be such a revolution in videogames, even as early as 1982. But videogames were young and mechanical puzzles were old, and the love child of the two couldn't help but be influential. Soko-Ban's top-down perspective seemed like any other block-slider, but with a "man on the inside," puzzlers had to think in entirely new ways. Extreme foresight is needed to make sure that the warehouseman can get behind every box when he needs to—a box along a wall will stay along that wall until the end of the game. And since these massive crates are apt to completely block off key passages, it is disturbingly easy to trap oneself behind a line of boxes. The real puzzle is getting the warehouseman around the labyrinthine storage space, pushing around the crates is simple after that.

The videogame is enables another important rule: the warehouseman can only push one block at a time. Remember that in sliding puzzles, like the 15 puzzle, you can move any number of squares at the same time, as long as they're not blocked by a wall. A square can't be movable from one position and then immovable from another. But the computer can keep track of changes like that, and two blocks forming an immovable deadlock was a novel twist that was much easier to keep track of in a virtual space.

When you consider all of these blocked passages and impossible-to-move boxes, the generally small puzzle grid starts to unfold into a massive maze of possibilities. The first level of Soko-Ban (shown above) takes over two hundred moves to complete. Others of Soko-Ban's original fifty levels take more than a thousand.

Attack of the Soko-Fans (Also, Clones)

Hexoban by David W. SkinnerThe level editor was another key feature of Soko-Ban, and dedicated players have been using it ever since. Many of Thinking Rabbit's sequels to Soko-Ban (Sokoban Perfect and Sokoban Revenge for PCs; Boxxle and Boxxle II for the Gameboy; and even a few releases on consoles like the Playstation) have featured levels designed by fans. Today, excellent amateur designers like David W. Skinner make their creations available over the internet.

Like most puzzle games with simple rules and low graphical demands, Soko-Ban has been cloned over and over and over again. One webpage has listed over eighty different implementations of Sokoban, which has become the name of the generic puzzle. Some of these programs, like SokoSave are designed to aid in the sharing of Sokoban levels and solutions. But many of the clones aren't just Sokoban, they're Soko-Ban with different skins. While it's considered questionable but generally kosher to clone a game mechanic, the level design is a different matter, and a number of these clones take Thinking Rabbit's original fifty levels with neither permission nor attribution.

The Sokoban community has gone beyond designing new levels to design new variants. David W. Skinner also created Hexoban, which is Sokoban on a hexagonal field. Trioban (Sokoban on a triangular field, where triangular boxes are pivoted instead of outright pushed) came from Fran├žois Marques. And then there's Malcolm Tyrell's Multiban, in which the lonely avatar has finally hired some more warehousemen to help move the boxes. Other games like Cyberbox and Block-O-Mania add gimmick blocks and grid spaces (one-way spaces, teleporters, etc.) to create new challenges.

Crates to Seconds

Sokoban in NetHack for Windows - Graphical InterfaceEven beyond the clones and variants, Soko-Ban inspired a number of item-pushing puzzle games. In 1985, the Eggerland series (known in America as The Adventures of Lolo and its sequels) began using crate-pushing as the core of its puzzles, which also involved collecting items and dealing with enemies. Even action games have incorporated Sokoban. Link invariably has to push crates into position somewhere in each Legend of Zelda game (The Wind Waker even featured an elementary Trioban segment). And the action-packed roguelike NetHack sports a Sokoban sidequest.

In today's more immersive games, crates aren't just for pushing; they're for pulling and climbing and smashing and gravity-gunning. In the mainstream, crate-pushing has become cliché. But that's only because the crates of first-person shooters and adventure games don't get pushed around enough. Action-game blocks are usually present only as an annoyance for a few minutes, but a difficult, well-designed Sokoban level can take hours of work over the course of days. It's far more frustrating, but on the other hand, it's far more rewarding to finish a level and know that you're done, not just moving on to better-designed parts of the game.

[Tony Delgado is a member of the National Puzzlers' League, and a solver and creater of puzzles of all sorts. He also works as the Copy Chief of The Gamer's Quarter.]