Editing Zork (section)

==Development==
===Inception===
{{multiple image|perrow = 2|total_width=300
| image1 = MBlank2018.jpg
| alt1   = Man standing
| image2 = Bruce Daniels.jpg
| alt2   = Man sitting at desk
| image3 = Dave Lebling.jpg
| alt3   = Man presenting at podium
| footer = Marc Blank in 2018, Bruce Daniels in 2009, and Dave Lebling in 2010
}}

[[Tim Anderson (programmer)|Tim Anderson]], [[Marc Blank]], [[Bruce Daniels]], and [[Dave Lebling]] began developing ''Zork'' in May 1977. The four were members of the Dynamic Modelling Group, a computer science research division at the [[Massachusetts Institute of Technology]] (MIT) Laboratory for Computer Science{{emdash}}Anderson, Blank, and Daniels as students and Lebling as a research staff member.<ref name="GDCTalk"/> Their work was inspired by ''[[Colossal Cave Adventure]]'', a text-based game that is the first well-known example of interactive fiction and the first well-known [[adventure game]]. ''Adventure'' was immensely popular among the small population of computer users of the time and a big hit at MIT in early 1977.<ref name="TCW383385"/> By the end of May, players had managed to completely solve it.<ref name="History1"/>

The four programmers began to design a game that would be a "better" text adventure game, with inputs more complex than ''Adventure''{{'}}s two-word commands and puzzles less obtuse.<ref name="History1"/> They believed that their division's [[MDL (programming language)|MDL programming language]] would be better suited for processing complex text inputs than the [[Fortran]] code used in ''Adventure''.<ref name="History1"/><ref name="Compute1983"/> The group was familiar with creating video games: Blank and Anderson had worked on a multiplayer trivia game called ''Trivia'' (1976), and Lebling was heavily involved with ''[[Maze (1973 video game)|Maze]]'' (1973), a multiplayer [[first-person shooter]] and the first 3D first-person game ever made. Lebling first created a [[natural language processing|natural language input]] system, or parser, that could process typed two-word instructions. Anderson and Blank built a small prototype text game to use it.<ref name="History1"/><ref name="GDCTalk"/> ''Zork''{{'s}} prototype was built for the [[Digital Equipment Corporation]] (DEC) [[PDP-10]] [[mainframe computer]], the only system that supported their programming language.<ref name="History1"/>

While Lebling took a two-week vacation, Anderson, Blank, and Daniels designed an adventure game concept, which Anderson and Blank then developed as an early version of ''Zork''. This prototype contained simple versions of many concepts seen in the final game, including puzzles and locations. According to Anderson, "it took time for people to learn how to write good problems", and Lebling's first, uncomplex parser was only "almost as smart as ''Adventure''{{'}}s". The game was unnamed, but the group had a habit of naming their programs "zork" until they were completed, a term in the MIT community for an in-development program. The group, referring to themselves as the "implementers", continued working on the game after Lebling returned, adding features and iterating on the parser through June 1977.<ref name="History1"/> Grues were added to replace pits that would kill players in the dark; while play-testing, Lebling noticed that his character fell into a pit while in the attic of the house.<ref name="GDCTalk"/>

Lebling contends that ''Adventure'' was one of ''Zork''{{'}}s only influences, as there were few other games to emulate at the time. Although the game's combat is based on ''[[Dungeons & Dragons]]'', Lebling said the other developers had never played it.<ref name="Retro77"/> He also thought of the parser and associated text responses as taking on the role of the Dungeon Master from a ''Dungeons & Dragons'' game, trying to lead the player through a story solely by describing it; this had also been the idea behind the parser in ''Adventure''.<ref name="USG2015"/><ref name="Dibbell5657"/>

===Creation===
The developers did not announce their game while it was in development, but a lack of security on the MIT systems meant that anyone who could access the PDP-10 computer over the [[ARPANET]] could see what programs were being run. As a result, a small community of people, many of whom had been involved in playing and contributing to ''Trivia'', would "snoop" on the system for new programs. They found the new "Zork" adventure game and spread word of it under that name.<ref name="GDCTalk"/><ref name="History2"/> This community{{emdash}}dozens or possibly hundreds of players, according to Lebling{{emdash}}interacted with the developers as they created the game, playtesting additions and submitting [[software bug|bug]] reports.<ref name="Retro77"/><ref name="History2"/> The implementers added a command transcript feature to keep track of what commands players tried to use unsuccessfully.<ref name="Retro77"/>

By the end of June, the game was approximately half the size of the final ''Zork'', and had a substantial community of players for the time. The group added locations such as a volcano and coal mine, and soon shifted their efforts to improving the [[game engine|game's engine]] and adding the ability to [[saved game|save the player's progress]] in the game. Following user requests, they also added the ability for the game to run on PDP-10 computers running different operating systems{{emdash}}[[TENEX (operating system)|TENEX]] and [[TOPS-20]]{{emdash}}which were much more popular than the [[Incompatible Timesharing System]] operating system the MIT computer used. These users then set up a mailing list to distribute updates to the game. The developers returned to creating new content in the fall of 1977, adding the "Alice in Wonderland" section and a system for fighting enemies.<ref name="History2"/>

Around this time, community member Ted Hess at DEC decoded the [[copy protection|protections]] the group had made for the [[source code]], and another DEC employee, Bob Supnik, created a [[Porting of video games|port]] of the game to Fortran.<!--Specifically, the team had changed ITS itself to hide the Zork directory from users, and also encrypted the source code; Hess found the ITS patch, undid it, and downloaded the game files (getting caught in the process by Anderson), and then brute-forced the encryption later.--> This port, released in March 1978, opened the game to a wider set of players without access to a PDP-10 mainframe.<ref name="History2"/><ref name="GetLampSupnik"/> At the time, the team had decided to give the game an actual name besides "zork", and chose ''Dungeon''. This name was used for the Fortran version, which was spread through [[DECUS|the DEC users group]] as one of its most popular pieces of software. [[TSR, Inc.|TSR Hobbies]] claimed the title violated their trademark for ''Dungeons & Dragons'', and the developers reverted to their original title.<ref name="History2"/>

Over the course of 1978, the team added the bank and Royal Zork Puzzle Museum sections, along with some puzzles and ideas suggested by players. The last puzzle was added in February 1979, though the team continued to release bug fix updates until the final update in January 1981. Anderson attributes this to the team running out of ideas and time, and having run out of space in the one [[megabyte]] of [[computer memory|memory]] allocated for the game.<ref name="History2"/>

Very little of the game was planned ahead of time, nor were aspects of the game specific to one developer; instead, whenever one of the developers had an idea they liked, that developer would add it to the game, developing the concept and writing the text to go with it. According to Lebling, Blank ended up focusing mostly on the parser, Anderson on the game code, Blank and Daniels on new puzzles, and Lebling on descriptions of locations.<ref name="Retro77"/> Anderson says that Blank wrote "40 or 50" iterations of the parser, and describes Daniels as designing puzzles that were then largely implemented by the others. He credits Blank with vehicles and saving, and Lebling with the robot, grues, and the fighting system.<ref name="History2"/> To immerse the player in the game, the developers decided not to describe the player character, removing any accidental descriptions or [[gender pronoun|gendered pronouns]].<ref name="Retro77"/> The text responses to the player's commands were frequently opinionated and sarcastic, a design choice that mirrored the group's speaking patterns. The team felt it would both make the system feel less like a computer and also train the player to write commands in a way that the parser could understand rather than ways it would misinterpret.<ref name="USG2015"/>

===Infocom===
In 1979, Anderson, Blank, Lebling, and five other members of the Dynamic Modelling Group [[incorporation (business)|incorporated]] Infocom as a [[software company]] for members to join after leaving MIT.<ref name="Globe1984"/> No specific projects were initially agreed upon and Infocom had no paid employees, but discussions were focused on developing software for [[minicomputer|smaller mainframe computers]].<ref name="Globe1984"/><ref name="History3"/> Blank and Joel Berez came up with a plan to make ''Zork'' work on personal [[microcomputer]]s, which were then beginning to become popular and which would greatly expand the audience for the game. Although microcomputers had very limited memory space compared to mainframe computers, they felt the project might be viable using [[floppy disk]]s and a custom programming language if the game was cut into two pieces.<ref name="History3"/>

The pair worked on the project through the summer and fall of 1979 without pay, as the new company had the funds for only the computers. They ported the game to a new Zork Implementation Language (ZIL), which would then be run on a standardized "[[Z-machine]]" software-based computer. For each type of microcomputer they wanted to release ''Zork'' or other ZIL-based games on, they could write an interpreter program that could run the Z-Machine instead of rewriting each game. Lebling divided ''Zork'' in half to create standalone episodes, modifying the game's layout to improve its flow and disconnecting locations now in separate episodes.<ref name="History3"/>

By the end of 1979 Berez had been elected the company's president. The core game was complete, but it had been run only on [[DECSYSTEM-20]] and [[PDP-11]] mainframe computers. Infocom purchased a [[TRS-80]] personal computer early in 1980, which could run the game after Blank and Scott Cutler created an interpreter program. Infocom began preparing to release the first section under the title ''Zork: The Great Underground Empire{{snd}}Part{{spaces}}I''. Mike Dornbrook, who had never played the game, tested it as an audience surrogate. He felt that the game would be wildly successful and develop a cult following, and urged Infocom to produce tie-in products like maps, hints, and shirts. The rest of the company was not convinced enough to start producing any such add-ons, but they did add an object in the game that gave an address for players to mail in for maps and hints in case it proved popular.<ref name="History3"/>

The game now complete, the company began looking for a professional publisher with store and distributor connections. They felt this was preferable to [[self-publishing]]. Berez approached [[Microsoft]], who declined based on the game competing with ''[[Microsoft Adventure]]'' (1979), their version of ''Adventure''. Microsoft CEO [[Bill Gates]] was a fan of ''Zork'', but by the time he heard of the proposal, Infocom was in negotiations with another publisher, [[VisiCorp|Personal Software]], one of the first professional software publishing companies. Personal Software agreed to publish the game in June 1980, sending the company an [[advance payment]]. ''Zork: The Great Underground Empire'', also known as ''Zork{{spaces}}I'' or just ''Zork'', was published for the TRS-80 in December 1980. Since Personal Software declined to publish the 1979 PDP-11 version of the game, Infocom sold some copies earlier in the year after announcing it to PDP-11 user groups. Lebling later recalled that about twenty floppy disk copies were sold directly with Anderson's typewritten manual.<ref name="USG2015"/><ref name="History3"/>

By the end of 1980, an [[Apple II]] version of ''Zork{{spaces}}I'' was completed and sold through Personal Software. Infocom began receiving requests for hints and maps as predicted, and Berez began handling map and poster orders while Dornbrook wrote customized hints for players; in September 1981 he founded the Zork Users Group as a separate company to handle all [[mail order]] sales and hint requests.<ref name="History3"/><ref name="ZUGorderform"/> Infocom eventually produced hint booklets with progressive answers to questions written in [[invisible ink]], branded as [[InvisiClues]].<ref name="History3"/><ref name="PCM1983"/> Meanwhile, Lebling worked on converting the second half of ''Zork'' into ''Zork{{spaces}}II'', but in the process thought up several new puzzles for the game.<ref name="History3"/> Although as late as December 1980 he told ''[[Byte (magazine)|Byte]]'' that it would be a two-part game, it soon became clear that the second half would not fit into the allotted space.<ref name="BYTE1980"/> As a result, the game was split again into ''Zork{{spaces}}II: The Wizard of Frobozz'' and ''Zork{{spaces}}III: The Dungeon Master''.<ref name="History3"/> According to Lebling, splitting the game into episodes led to different atmospheres: ''Zork{{spaces}}I'' was focused on exploration and ''Adventure''-style gameplay, ''II'' had more of a focus on plot and added [[magic spell]]s to the base game, and ''III'' was less straightforward, with time-sensitive aspects.<ref name="Retro77"/> Marc Blank constructed ''Zork{{spaces}}III'' and added gameplay changes such as the modified point system to move the game away from straightforward dungeon exploration.<ref name="GDCTalk"/>

''Zork II'' was offered to Personal Software in April 1981 and the contract was signed in June, but Infocom grew wary of continuing this relationship. The Infocom team felt that Personal Software was not advertising ''Zork{{spaces}}I'' very strongly, and did not seem excited about Infocom's plans for ''Zork{{spaces}}III'' and other planned text adventure games such as ''[[Deadline (1982 video game)|Deadline]]'' and ''[[Starcross (video game)|Starcross]]''. Personal Software soon stopped publishing entertainment software altogether and rebranded as VisiCorp in 1982 to align with its [[VisiCalc]] spreadsheet software. Rather than find another publisher, Infocom decided to self-publish its games and began renting office space and contracting with production facilities. It bought out Personal Software's stock of Apple{{spaces}}II ''Zork{{spaces}}I'' copies and began publishing ''Zork{{spaces}}I'' and ''II'' directly by the end of 1981. ''Zork{{spaces}}III'' followed in the fall of 1982. Infocom developed interpreters for the [[Commodore 64]], [[Atari 8-bit computers]], [[CP/M]] systems, and [[IBM PC compatible]]s, and released the episodes of ''Zork'' for them as well in 1982.<ref name="History3"/>