Interactive Fiction and Adventure Games

Computer gaming can be traced back to the earliest experiments in computer artificial intelligence from the 1940s. The earliest games were primitive adaptations of traditional competitive games such as Nim (1951), OXO (1952), and Tennis for Two (1958). Spacewar! (1962) is often credited as the first commercially successful and widely available computer game, which influenced the next generation of arcade games like Pong (1972) and Gun Fight (1975). Star Trek (1971), Hunt the Wumpus (1972), and dnd (1975) shifted game focus from multiplayer competition to single player problem solving. Following in the path of these titles, 1977’s Adventure gave birth to a new genre, the aptly named adventure game. Adventure games are characterized by their rich interactive single player environment, often with goals of exploring one’s surroundings, solving difficult puzzles, and collecting treasure.

In the early 1970s, Willie and Patricia Crowther were employed by Bolt, Beranek and Newman (BBN). Both were amateur cavers and had extensively explored the Colossal Cavern and Bed Quilt Cave in Kentucky. At BBN, Willie was developing assembly software for the original routers used in ARPANET, and when Willie and Pat had divorced in 1975, Willie wrote a game that he could enjoy with his daughters. The game was based both on his caving experiences and certain fantastical elements inspired by the Dungeons and Dragons tabletop game. Over the 1975-1976 academic year, Crowther wrote the earliest version of Adventure in FORTRAN on BBN’s PDP-10 timesharing computer. While Crowther abandoned development on the game sometime in 1976, the game quickly spread through ARPANET and was discovered by Don Woods of the Stanford Artificial Intelligence Laboratory. In late 1976 or early 1977, Woods contacted Crowther to request his source code, and began work on expanding the game in March 1977. By May of 1977, Woods had greatly expanded the magic, humor, simple combat, and puzzles, of the original game. The Crowther/Woods version was ported to C by Jim Gillogly in later 1977, which allowed it to easily run on UNIX systems, and was widely distributed, and further ported to other systems.

Adventure is able to parse two word commands in VERB – NOUN format; i.e. GO NORTH, GET CAGE, or DROP STICK, although limited to five characters per word (the game instructs the user to use “NE” in place of “NORTHEAST”). As an anonymous Adventurer, the player must explore a vast system of caves, solve puzzles, and collect all the treasure to receive all 350 points. The world is broken down into a number of rooms which are interconnected amongst one another, sometimes in a non-linear fashion, by directional points (N, W, E, S, etc). Rich descriptive text is provided for each room, as well as the various items and entities in them.

Adventure made its way to MIT in 1977, and when a number of hackers including Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling had solved the game, they looked for ways that they could improve it. Dissatisfied with the simplicity of FORTRAN, Lebling wrote a parser in MUDDLE, a language that was a successor to LISP, on a DEC PDP-10. The new advanced parser handled more complex sentences beyond a simple two word VERB-NOUN format. The increasingly complex interactions between the player, the world, and its objects eventually took shape into a game much larger than Adventure. This new game was initially called Zork, a nonsense slang word used for unfinished programs meant to be later installed on a computer when in a finished state. The name of Dungeon was decided upon in 1977, but was short lived; Tactical Studies Rules sent the developers a trademark infringement notice, claiming Dungeon bore too much similarity to Dungeons and Dragons, and the name was changed back to Zork.

MS-DOS version of Zork I

The 350 point Crowther/Woods Adventure as ported to AGT Markup Language. This was one of four games included with the software tool as a teaching example of the Standard Level implementation which was advertised as requiring no previous programming experience.
Zork’s original code in MUDDLE limited its playability to DEC PDP-10 computers. With the rise of personal computers in the late 1970s such as the TRS-80 and Apple II, a large group of computer users could not easily play the game. A FORTRAN port was released in early 1978 by Bob Supnik, a DEC employee who had obtained a leaked copy of the source code. This allowed the game to run across multiple platforms, ironically as FORTRAN was viewed as clunky and limiting by Zork’s initial designers. A custom programming language called Zork Interactive Language (ZIL) was developed in 1979 by Joel Berez and Blank to both port the game easily across multiple platforms, and to serve as a development tool for future games.

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