The first time I played the tabletop game Fiasco, it wasn't the story my friends and I made that blew me away. It was the realization that I had just experienced the limitless possibilities of collaborative writing, that the novels I loved featured just one way their narratives could have played out. Alice could have transformed the Mad Tea Party into Wonderland's first organic tea shop. Don Quixote could have devolved into a windmill-killer for hire. Later I realized the similarities between tabletop games and ways novelists challenge their narrative choices, from literary constraints to automatic writing to William Burroughs' cutup method.

Dupin's pinned a homicide on you." Special Agent Dinah Carter and I had worked on only a couple of cases as partners in the FBI. Now she was programming me for survival mode, to elude the bureau's AI-based crime-solving system, Dupin. "Lose your phone," Dinah told me. Dupin had named me prime suspect in a crime that had occurred just moments before and miles away because I had guessed that the AI was fabricating evidence. I didn't realize then how soon I'd be declared dead. I took the emergency stairs to street level, dropping my cell phone behind a fire hose. With my hood up and watching out for security cameras, I headed onto 10th Street Northwest. When I gave the barista cash for my half-hour online and thimbleful of espresso, he looked at me as if I was something he needed to wipe off his shoe. That left me with a dollar and some loose change. I sat down at a screen and pulled out the AI Primer that Dinah had given me. In the back were the author's details--Professor Francesca Adriaco from Georgetown University. If I had any chance of surviving this, I needed her help. I need to speak with you urgently about artificial intelligence. I guess she had a system monitoring her emails; she replied in minutes and invited me to her office. If I ever survived this, I needed to exercise more. "Hey, Saskia, good to meet you.

Carter shook her head and stared at the combined camera and microphone that surveyed the corridor. Lipcott's words seemed to float in front of her eyes. What she did next could determine not just Lipcott's future, but her own. She walked on to the corner, to a dead spot between cameras, took a deep breath, and mouthed, "Don't ask questions.

In this paper, we address the problem of change in an abstract argumentation system. We focus on a particular change: the addition of a new argument which interacts with previous arguments. We study the impact of such an addition on the outcome of the argumentation system, more particularly on the set of its extensions. Several properties for this change operation are defined by comparing the new set of extensions to the initial one, these properties are called structural when the comparisons are based on set-cardinality or set-inclusion relations. Several other properties are proposed where comparisons are based on the status of some particular arguments: the accepted arguments; these properties refer to the evolution of this status during the change, e.g., Monotony and Priority to Recency. All these properties may be more or less desirable according to specific applications. They are studied under two particular semantics: the grounded and preferred semantics.