The Line / The Line Interactive Fiction and Symmetry in Human-Computer Text Exchange Nick Montfort Presented 14 August 2001 in the panel The Pixel / The Line: Approaches to Interactive Text ACM SIGGRAPH 2001 Art Gallery: N-Space, Los Angeles *** Interactive Fiction and Interface Symmetry ********************************************** In interactive fiction, a form that began with the combined cave simulation and computerized riddle [1] -Adventure-, the system provides lines of text; the interactor responds with lines of text. The response is usually a short and direct command, while the computer's text may at times be lengthy and lavishly descriptive. Nevertheless, a purely textual system likes this provides for an interestingly symmetrical interaction. Brenda Laurel writes that "the desire for symmetry between 'input' and 'output' modalities is strong," [2] and even when the same modalities are used for input and output the user may wish that she has the same types of expressive abilities as does the computer. In my work, I have tried to further this symmetry in all possible ways that my development resources allow and that are suitable to the purposes of my works. [3] My experiences, although they did not result in a situation of true co-authorship between the interactor and the interactive fiction work, are likely of interest to those involved in the art of interactive fiction authorship. I hope they also may be of use in thinking about human-computer interface in general, and in graphical, haptic, audio, and other systems as well as in textual systems. "Interactive fiction" describes a system that simulates a world programmatically and that accepts natural-language text input, providing text in reply. This clearly includes text adventures (although an element of "adventure" is not required for something to be interactive fiction) such as those created at Infocom during the 1980s, including the top- selling -Zork I, II- and -III- by Marc Blank and Dave Lebling, 1980, 1981, 1982 and -The Hitchhiker's Guide to the Galaxy- by Douglas Adams and Steven Meretzky, 1984. [4] This definition excludes Eliza/Doctor (since there is no world or setting through which the interactor can effect movement) and the usual graphical adventure game (since text is not the medium of interaction). Interactive fiction is not the only fiction is that interactive, any more than language poetry is the only poetry that is language, but the term has long been used as a whole specifically to denote works of this form. During a session of interaction, somewhat similar texts are exchanged by computer and interactor. The interactor studies the computer's text to see what the environment of the player character is like, to pick out things that might need to be examined or manipulated in order to progress, and to try to discover the nature of the simulated world and its challenges. The system, during this session, parses each reply to understand the curt but natural-language commands, translating them into actions of the player character in the interactive fiction world. The interactor types some of the same words that are output in order to examine or manipulate things in the simulated world; the system replies, at times, directly quoting what the interactor has typed. Computer and human are making genuine attempts to understand the texts that are being exchanged -- in the sense of those types of "understanding" that computers today effect; the text is understood within the domain described by the simulated world. This is certainly not the same situation as in a graphical adventure game -- for instance, -Myst-. When an almost photorealistic rendered image of an island is presented to the -Myst- interactor, he does not respond by drawing an almost photorealistic image of what he wants to do and then holding it up to the computer. This is an option, of course, but it does nothing; it has a similar lack of effect as does writing "DIG IN THE SAND" in the margins of -Alice in Wonderland-. The interface in -Myst- only provides for the interactor to point and click. This clearly is more efficient in many circumstances than is typing; clicking on an image of a simulated kitchen in order to go there is usually simpler than remembering it is located to the northeast and then typing "NE". The point-and-click interface, however, does not provide the same symmetry of interface. My interest in interactive fiction is not due entirely to its interesting qualities of interaction, such as symmetry; I also believe that interactive fiction is no cyber-archaeological curiosity but a compelling framework for literary and ludic art, original to the late 20th century and woefully underexplored. [5] One doesn't have to concur, however, to consider some aspects of interface illuminated by my experience with interactive fiction. Of course, the idea of a symmetrical interaction is clearly seen in many other systems based on human conversation. Chatterbots, following the influential Eliza/Doctor, are more extreme textual examples of symmetrical interaction. In graphical embodied conversational agents, the agent may produces gaze, facial expression, gesture, and speech in response to the detection and interpretation of user communications using the same modalities. Interactive fiction is not worthy of general attention because it is unique but because it has been overlooked, and because insights from experience in this form may aid in the development of other systems dealing with symmetrical interaction. *** -Winchester's Nightmare- **************************** In October 1999 I released -Winchester's Nightmare: A Novel Machine- and showed a few copies from the hardback edition at Digital Arts and Culture 99 in Atlanta. Many of those outside the interactive fiction community but interested in literature and computer, whom I hoped would enjoy interacting, had convened there. (I also hoped the work would be appreciated by members of the interactive fiction community, but I made a conscious attempt to reach a new group of pro-computer readers of literary fiction.) -Winchester's Nightmare- is an involved work, more the length of a novel in terms of how long a complete experience of the work takes. The hardback, produced in an edition of ten, consists of a primitive portable computer running -Winchester's Nightmare-. The 'softback,' like -Ad Verbum- and all of my electronic literature work, is available for free at . Both works are programmed in Inform, an object-oriented language for writing interactive fiction. Inform is by Graham Nelson, 1993; it compiles to run on Infocom's virtual Z-Machine (devised by Joel Berez and Marc Blank), allowing it to run on more than twenty different platforms. The source code for the Inform compiler is available, as are libraries, including code for a standard parser; there is no charge for any of it. -Winchester's Nightmare- uses libraries I customized for the work. The canned responses to certain actions were replaced with responses that are consistent with the style of the other text in -Winchester's Nightmare-. My customizations also change the point-of-view to third person. A third-person work means that both interactor and computer can, symmetrically, refer to the player character, Sarah Winchester, [6] in the declarative; normally the interactor types commands in the imperative. An important interface idea in -Winchester's Nightmare- was to work towards a more co-authorial relationship in small but hopefully important ways at the interface level, trying to increase the symmetry of interaction at every opportunity. [7] Structurally, the interactor does not have a much larger role than in the standard text adventure. Certain other interactive fiction works clearly provide more interactor influence over plot: the branching story in Adam Cadre's -I-0-, 1997, and the branching conversation in Emily Short's -Galatea-, 2000, for example, are controlled by the interactor to a much greater degree than is the plot in -Winchester's Nightmare-. I decided instead to created a large space which few would explore exhaustively, and have a set of challenges which may be overcome in a different order but which all must be met in order to bring the complete interactive experience of the work to its conclusion. Since the world is expansive, each interactor may determine a different experience by deciding where to go and what to look at, in what order. I replaced the standard ">" prompt with language -- "Sarah decides to" -- in order to make the reader's contribution continuous and to make the shape of the text that appears more like usual prose, as seen in Figure 1. The usual directional commands (such as "north", "down", and "in") are never required. The only way to move to landmarks within "cities" (actually regions of a large city, located along a loop on a linear island) is by typing "go to (landmark)", "enter (landmark)", or a similar text; the areas are not accessible by means of compass directions. Although the setting ranks among the largest in all interactive fiction, it is laid out so that mapping on paper will be unnecessary. During testing several interactors new to interactive fiction completed the work without drawing a map. The usual abbreviated commands (such as "e" for "east" and "l" for "look") are not implemented, much to the chagrin of those in today's interactive fiction community who tried -Winchester's Nightmare-. If a standard text adventure abbreviation is typed, this reply is forthcoming: "This abbreviation does not signify in this dream. For Sarah to act, she will have to think in whole words." Although cruel to the interactor who is used to the conventional interface, the idea was to assume an exchange of prose, recasting the interaction from the usual command and response mode that looks more like a Unix shell than like a page from a novel. A different and more clever approach to this issue was taken in -Ad Verbum-. The descriptions of Sarah's surroundings, a dreamscape, are intentionally written in a very terse style, to minimize the disparity between the length of computer-contributed and interactor-contributed text. The contributions are still in many ways unequal, but here too the attempt was made to increase symmetry. All of the structures that exist in the setting and are mentioned in descriptive text in -Winchester's Nightmare- are implemented and may be referred to, meaning each exists as a programmatic object of an appropriate class and a reasonable reply is provided to all commands involving it. (This does not mean that manipulating or examining such objects is always useful in solving the overall riddle or appreciating the work.) All of their architectural elements that are mentioned or that are obviously implied (e.g., when inside a building a ceiling, a floor, and walls will be visible in most circumstances) also are implemented and may be referred to, down to the level of materials (e.g. brick, granite). Even then, while Sarah cannot "examine the granite", if she is near a granite building she will be able to "examine the granite building" as distinct from the nearby brick building. Furniture and elements of the landscape are similarly implemented. In general, with the exception of materials, an attempt was made to implement everything mentioned in -Winchester's Nightmare- so the computer's generated text never refers to things that the interactor cannot also meaningfully refer to. This is to eliminate what Infocom manuals referred to as "purple prose" -- descriptive text mentioning things that are not part of the simulated world. Anyone who has reached the conclusion of -Winchester's Nightmare- will note another way in which the work provides an interesting new role for the interactor, but to say more would spoil the pleasure of completing -Winchester's Nightmare-. --- FIGURE 1 --- South City Sarah is among neat white buildings by a calm tree-lined street. The eastern branch of the river runs by. A wide track leads northeast to Civic District and southwest to Lone City, while a farm road leads northwest. Within are: a plantation, the French quarter, and residence row. Sarah decides to go to Lone City. Lone City Sarah is by a dusty street. The wooden facades around are two stories tall, but the windows of the second story look through to the sky. The river's two branches join just to the south. To the northwest, a wide track stretches on to the City of Dreams, while it runs northeast to South City. Within are: a plain and an old church. Sarah decides to look at the windows. She looks around at the wooden facades, shuttered and closed on the first floor. A few of the second-story shutters have come open, revealing the sky. These all are one-story buildings, with a false second story installed above. Sarah decides to close the shutters. They are not something she can close. Sarah decides to go to the church. Church Entrance Sarah is on the southern side of an ancient church. The facade, rounded into a bell shape at the top, is made of yellow, pitted limestone. A hand- lettered banner is strung across the front. The immense wooden doors, stained dark brown, are cracked open. A Mexican army is assembled some distance away. She can leave to Lone City. Sarah decides to look at the sky. The sky is a dark, gritty blue, broken by wisps of gray. The sun is halfway up in the east. Sarah decides to stare into the sun. The massive disk of the sun burns through the sky's grit. Staring at it, Sarah sees total blackness for a moment. She has not lost her vision, though. Instead, the whole sky has darkened in an instant. The sun has vanished, as if an eclipse has occurred. Church Entrance Sarah is on the southern side of an ancient church. The facade, rounded into a bell shape at the top, is made of yellow, pitted limestone. A hand- lettered banner is strung across the front. The immense wooden doors, stained dark brown, are cracked open. Police, some in riot gear, stand or mill outside. She can leave to Lone City. Sarah decides to read the banner. The letters spell out a short sentence: "You evict us never." --- CAPTION: A transcript from -Winchester's Nightmare.- The text that completes each line beginning "Sarah decides to" was typed by the interactor. *** -Ad Verbum- *************** My second work is very different from -Winchester's Nightmare-. With only a vestige of a plot, a player character barely distinguished from the nameless, faceless, genderless adventurer of early games such as -Adventure- and -Zork-, and a stereotypical, almost-empty mansion for a setting, -Ad Verbum- would be of very little interest indeed if its puzzles were not novel. -Ad Verbum-'s puzzles were appreciated by interactors, though; it won the 2000 XYZZY Award for Best Puzzles. It was also the first place pick of interactive fiction authors who entered the 2000 IF Competition. These awards may reflect a different "ideal interactor" imagined when composing -Ad Verbum-: someone familiar with the form and interested in a different way of playing with language. The player character in -Ad Verbum- is tasked to clean out all the objects from the residence of the now-evicted Wizard of Wordplay, depositing them in a Dumpster that is a mockery of -Zork's- trophy case. To do this, the interactor must overcome obstacles more familiar to the Oulipo [8] than to 20th-century text adventurers. Some wordplay precedents in interactive fiction exist, such as -Nord and Bert Couldn't Make Heads or Tails of It- by Jeff O'Neill, Infocom, 1987 and -T-Zero- by Dennis Cunningham, 1991. None, however, had set up a symmetrical constraint on text production that was to be followed by the computer and interactor both, as in -Ad Verbum-. Various puzzles requiring certain types of verbal production are installed throughout the mansion. The rooms off the main lobby on the "initial floor," are described in text that is hyperalliterative, for example. Furthermore, all the messages that the computer produces in these rooms also have only words that begin with the appropriate letter. Only text from the interactor that follows a similar constraint will be accepted as input, as seen in Figure 2. Unable to issue the commands "look", "get", or even "exit" or "north", the interactor faces the challenge of writing in an appropriate way while also instructing the adventurer to carry out the appropriate task and to leave the room. Many of the interface innovations in -Winchester's Nightmare- were not carried into -Ad Verbum-, but this for the most part was not because I found them fruitless but because they did not suit the small indoor setting, the different population of interactors I had in mind, or the tone and concept of my shorter second work. Because certain rooms in the -Ad Verbum- mansion appeared under textual constraints, for instance, the standard analphabetic ">" prompt was much more suitable than a "The adventurer decides to" prompt would have been, since such a prompt would be prohibited from appearing in the Sloppy Salon and similar rooms. In -Ad Verbum- abbreviations (such as "e" for "east") may be used but the computer will follow the lead of the interactor and, if the interactor abbreviates, will abbreviate compass directions in descriptive text ("A living room is e. On the s side is the front door.") to maintain the symmetry of prose style. The stylistic symmetry-promoting innovations in -Winchester's Nightmare- may prove to be worth repeating in future work, but a more essential element of the work, the nature of the puzzles, has been given a symmetrical logological basis in -Ad Verbum-, in a way that seems to make the work fun and accessible. Having the interactor try to produce texts following the computer's lead, with the usual framework of adventure interaction underlying this game, was an effective use of a symmetrical interface. --- FIGURE 2 --- Initial Lobby The lobby of the mansion's initial floor - the one above the ground floor - is an ordinary and fairly well-maintained room. There are some things scrawled on the ground here, in the contractor's handwriting: '1 object' is written to the north, while toward the other three exits on this floor '2' is scrawled. The stairway that runs down to the foyer turns and continues up, to the next floor. The constrained passages to the south, east, west, and north look as if they might spell trouble. Or perhaps they simply spell 'SEWN.' >look at the stairs The stairway stands undemolished, ready to convey you in a vertical direction. You can just type that direction, as is traditional. A distracted figure with frizzy hair blunders in. The man is clad in loose clothing and peers at a fashion magazine he is holding open before him. On one page are some nicely-dressed women; the facing page has an image of some textile machine. The man mutters, partly to himself and partly as if he were addressing the magazine, "Girls, attractive dresses that loom here this second certainly second this here loom that dresses attractive girls." He blunders out, using motions that seem to be exactly the reverse of the ones he made when entering. By the time you've recovered from the shock, you realize he has completely disappeared. >south "LISTEN WELL!" a sonorous voice booms out, in attempted hollowness. "Know ye that passage back through here is difficult for some, impossible for others! Should you wish to transport yourself - without your cherished possessions - out of these constrained confines, utter the magic command: START!" Sloppy Salon Simple social space, sadly spoiled. Some skewed situation's sequel, surely. Seemingly, slovenly students sojourned -- scraping, scratching, scuffing surfaces. Stuff: ... stainless steel stapler... sizable sofa. >get stapler Stop! Stop! Show some sense. Scribble suitable strings. >look Stop! Stop! Sinful speech. Select superior symbols. >sit Sit? Sure. Sofa seems suitable. Sitting ... seated. >stand ... sweet, simple sofa sojourn. So ... standing. >staple sofa Stapling something? Stapler suggested. >see stapler Strong stainless steel surface seems smoothly solid. "Swingline," stapler says. Serviceable, slick, sure. Sadly, stapler seems sans staples. --- CAPTION: A transcript from -Ad Verbum-, with the interactor's text following the ">" prompt, as usual. *** Furthering Symmetry in Interactive Fiction ********************************************** The best way to demonstrate specific new ideas in interactive fiction, as the community of authors today agrees, is to simply implement them in a work and then talk about them later. Some interesting discussion has ensued before implementation, but I will restrict myself to suggesting two general principles that seem to follow from my experience of what I have already implemented. First, symmetry works best with essential aspects of interaction; it can irk when it is applied in ways that override interface conventions. The case of abolished abbreviations in -Winchester's Nightmare- makes this clear; interactors who did not appreciate the more prose-like framework did not find the symmetry a boon. In -Ad Verbum-, the same issue of symmetry and goal of a more prose-like experience was addressed in a more amusing and less odious way, while symmetry was successfully enhanced with regard to the creation of language in puzzle-solving situations. Second, different and compelling experiences are enabled by increasingly symmetrical interfaces. Many human games, and many other human experiences such as conversation, work well because the participants have symmetrical modalities and symmetrical ability to act and recognize within these modalities. Whether it is Ping-Pong, chess, or human-on-human -Quake-, a "level playing field" is seen as a precondition for many types of sport, game, and play, not to mention other non-game activities such as the resolution of disputes through the legal system and international trade. A Rogerian therapy session (lopsided in terms of its focus on one participant) was the framework for the first compelling and stylistically symmetrical chatterbot, but based on the reception of -Ad Verbum-, other symmetrical exchanges of text can offer a new set of unusual options, even if the interactor is constrained to non-obvious and less-than-natural interaction. ---------- [1] Although the term "puzzle," rather than "riddle," is typically associated with interactive fiction, I find the riddle is a better figure for the overall arrangement of challenges in the form. For example, a puzzle may be a physical object, an equation, or a verbal challenge; a riddle is always verbal and has a literary heritage, extending, in English, back to one of the earliest texts in the language, -The Exeter Book.- Many of the better riddles offer metaphors which one must understand in order to solve the riddle, as exploring a setting is necessary to determine the workings of an interactive fiction world. So although it makes sense refer individual challenges as "puzzles," a good interactive fiction work is, overall, more like a riddle than like a puzzle or game. [2] Laurel, Brenda. -Computers as Theater.- (118.) Reading, MA: Addison- Wesley. 1991. [3] I refer to "interactive fiction works" or "works of interactive fiction" or simply "works" rather than "games," although interactors and authors of interactive fiction themselves use the term "game," while acknowledging the form has other aspects in addition to its game-like aspect. Since the "game" nature of interactive fiction has been seen by some academics in the past in a reductionist way, and has led to almost automatic dismissal of the form in critical circles, when addressing an academic audience I prefer not to use the misunderstood term "game." [4] Interactive fiction works are cited by author and year, with the company that published them mentioned when applicable. In two cases the citation is too elaborate to mention in passing in the main text. -Adventure- is by Will Crowther and Don Woods, with Crowther's original version begun in 1972 and Woods' additions done beginning in 1976. -Zork- (a PDP-10 work that was briefly renamed -Dungeon- and was the basis for -Zork I-III-) is by Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling, first released in 1977. Many versions of both -Zork- and -Adventure- were released over the years, with some versions of the latter including substantial late additions. [5] Those willing to be persuaded about this should await Montfort, Nick, -Twisty Little Passages,- Cambridge: MIT Press, forthcoming. [6] As described on , the life of the historical figure Sarah Winchester, nee Pardee, 1837-1922, inspires the work. Sarah, who indirectly gave her name to the Winchester hard drive, is remembered for building onto her San Jose house constantly for more than thirty years, supposedly following the instructions of a spiritualist and seeking redemption for the many killings effected by the Winchester rifle, made by her husband's company. This Winchester Mansion is not portrayed directly in my work, which takes place instead in the composite metropolis of Sarah's dream, United City. Setting, which almost always has an enlarged role in interactive fiction when compared to the role it plays in the novel, is clearly the dominant element. This city is peopled with a few other characters; a plot (driven by Sarah's search for redemption) also organizes the narrative. United City is like Rockvil in Steven Meretzky's -A Mind Forever Voyaging-, Infocom, 1985: an American city, one which the main character sees as home, and one that is transformed through time. It is also like the landscape of Robert Pinsky's -Mindwheel-, Synapse/Broderbund, 1984, in that it is a "mental map" of a character's psyche. Exploration of the world reveals aspects of the player character and her particular obsessions. Some interactors have expressed a desire to have Sarah enact internal actions, to be able to think and feel in response to command. This misses an important point: Sarah's actions in her dream (already an internal affair) correlate to her inner thoughts and feelings. Rather than present a bag of puzzles to be solved, the one difficult, overarching problem symbolizes Sarah's guilt; her solution to this problem requires that the interactor engage with the setting and puzzle through certain American dilemmas. [7] Montfort, Nick. "Computer Co-Authors for Fiction." Presentation at Computers and Writing 2000, Fort Worth, Texas, 27 May 2000. Abstract at , full text at . [8] A French literary "workshop" devoted to the creation of potential literature, that is, systems for literary production. A good introduction to the Oulipo for the non-Francophonic is Motte, Warren F., Jr., editor, -Oulipo: A Primer of Potential Literature,- Univ. of Nebraska Press, 1986; Normal, IL: Dalkey Archive, 1998. A more encyclopedic resource is Mathews, Harry and Alistair Brotchie, editors, -Oulipo Compendium,- London: Atlas Press, 1998. --- END ---