Trust & Betrayal was a predecessor of the concept of interactive storytelling, a concept Crawford is currently pursuing. The name Siboot preserves the memory of Bootsie ("Siboot" is "Bootsie" with the syllables reversed), a cat which Crawford had, which had to be euthanized due to an irreparable injury to his jaw. Crawford suffered much grief while contemplating that he was unable to talk to Bootsie in order to try to comfort him, before he had to be put down. One day while pondering this, Crawford had a flash of insight: his next game would be Talk to the Animals, which evolved into Trust & Betrayal.
The original concept was very different from the final design, but the design still sprang from the designer's heart. The final design can be summarized thusly: The player, a creature named Vetvel, must compete with six other acolytes (each a different alien species) for the Shepherdship. Each of these characters a distict personality. Each morning, the acolytes wake up knowing one of each of the three "auras" the others possess. They must trade knowledge with each other in order to try to gain enough knowledge for the "mind combat" that takes place every night, which is basically a fancy rock/paper/scissors game that depends on the aura counts for the players involved. The game is won when a player gets eight auras in all three categories. The catch was that if you give away somebody's aura count, you are betraying that person. Therefore a player has to know whom to trust and whom to betray, hence the title: Trust & Betrayal.
The game had several major innovations. For instance, it featured an inverse parser, a method for constructing sentences out of words but only presenting words that make sense for the given context. It also placed some emphasis on facial expressions, as a visual form of feedback. It even had a primitive form of tool-tips: if you click and hold the mouse button on an icon (the game's abstraction of a word), you can see the meaning of the word, although the number of icons is small enough, and the pictures intuitive enough, that they can easily be committed to memory. It also featured what Crawford calls "interstital stories", interludes that appear through the game that present the user with one of several choices, some of which may affect the game. For instance, to use an actual example from the game, if game designer Chris Crawford appears and lectures the player, and the player responds "Go to hell, Crawford!", then the game becomes harder to win.
For all these innovations, Siboot didn't hold up very well in the marketplace, actually losing money. It sold 5,000 units on the Apple Macintosh. A preliminary IBM PC port was made but never finished; however, it can be found on the web, although it has some problems. Siboot's market failure is probably not due to any weakness of the design, but rather because it was extremely different from any computer game before then (some may even argue since then), therefore it didn't have a large, receptive audience. From a creative standpoint, however, Chris Crawford believes it was a success, and one of the best games he has ever designed.