(c) The New York Times BOOK REVIEW - May 8, 1983 READING AND WRITING By Edward Rothstein Participatory Novels When involved in a particularly vexing mystery, Sherlock Holmes would shoot a revolver into a wall, play his violin or take drugs. Hercule Poirot would drink hot chocolate and wax his mustache. Lord Peter Wimsey had his bottle of port and his attentive manservant. And I have my own criminological habits. I am currently involved in the Robner case. Spread before me are pills found near the body, a photograph of the chalked outline of the cadaver, the lawyer's letter about the will. But unlike my distinguished investigative predecessors, I forswear a violin, hot chocolate and the temptation to ring for my butler. I turn instead to the screen of my home computer. For the Robner case, unlike those of the Red-headed League or Roger Ackroyd, takes place in a different fictional medium. It is coded on a 5 1/4-inch magnetic disk used to store computer programs. The murder, the characters and the setting are all part of a computer game called Deadline. "Tell me about your father," I type on the keyboard, hoping a feckless suspect will confess to patricide. "Look, man," the words appear in reply, "I'm not going to lie to you and tell you I loved him, right? He got what ...." His voice trails off, accompanied by the gentle hum of the computer's motor. The investigation takes place on the screen through textual descriptions that appear in response to my typed questions and instructions. "Fingerprint the teacup," I write, and receive the results. "Answer the telephone." I type after it rings, hoping to overhear an incriminating conversation. I shadow suspects, hide in closets. And I am aided by evidence packaged with the computer disk -- the pills, the coroner's report, the photograph. But I am not some forensic Pac-Man, proceeding through a pre-existent maze. From my arrival at the Robner mansion, I am a character whose actions affect the world I enter. I arrest a suspect only to find that the grand jury isn't convinced by my evidence. I follow a suspect too obviously, and he just retires to his room. My questions can lead to a second murder -- and my carelessness to my own. But there is a unique solution. And to find it, I must often start the case over, re-experience it from different perspectives. The average complete investigation lasts 20 hours; I have spent many more exploring the program's intricate universe. Deadline, in fact, is more like a genre of fiction than a game. It is "published" by Infocom, a company founded by eight young M. I. T. computer scientists in 1979. Infocom has been a major pioneer in such games, which have been called "participatory novels," "interactive fiction" and "participa-stories." The main author (and programmer) for Deadline is Marc Blank, a 28-year-old vice president and co-founder of the company. The genre is not yet, of course, entirely flexible. Deadline contains 25,O0O words of text, but my comments and questions must be kept within the limits of a 600-word vocabulary and grammatically simple sentences. Solving the case involves learning the genre's formal rules; if I violate them, I am corrected. But as programming and data-storage techniques advance, Mr. Blank expects interaction to become more sophisticated, leading perhaps to the ultimate participatory novel. The form is already becoming popular, as computers become common in homes. Thirty-five thousand copies of Deadline have been sold in two years, at a list price of $49.95 each. The company's remarkable adventure fantasies, known as the Zork Trilogy, have been even better sellers. In 1982, Infocom sold about 100,000 copies of five different "participa-stories" coded for 13 personal computer systems, the sales yielding nearly $2 million in revenue. Their success should come as no surprise. For their worlds also happen to be the worlds of popular fiction -- the detective story, science fiction, adventure and fantasy. These genres define worlds with their own logic; they pose lucid ques- tions and possess clear narrative easily adaptable to a computer. In 1927, for example, the Russian formalist critic Vladimir Propp mapped out rules governing the structure of Russian fairy tales in his "Morphology of the Folktale"; in 1965, they were programmed into a computer. Infocom makes use of such forms, which have traditionally had archetypal power, and tempers them with irreverent wit. In Zork, the adventurer passes through a kingdom of magical and threatening chambers in almost Odyssean fashion. The detective of Deadline must also be a "man of many devices," interpreting signs, solving riddles. The classic detective novel itself may be a 19th-century bourgeois mythic tale, in which the detective -- an eccentric outside the social order, armed with magical powers of reason -- restores the transgressed boundaries of the social world. Sitting at the computer, my goal is more humble -- just to restore my composure. But a successful detective knows no rest. Stu Galley's The Witness, to be released by Infocom next month, has just arrived, complete with a detective gazette and the decadent atmosphere of Los Angeles in 1938. "Storm clouds are swimming across the sky," the computer tells me. "Your favorite pistol, a snub-nosed Colt .32, is snug in its holster. " "Come. Watson," I would type back in Holmesian fashion, if the program could understand, "the game is afoot."