This software is an educational demonstration of Natural Language Processing (NLP), an AI technology, as applied to the adventure game “The Portopia Serial Murder Case” (created by Yuji Horii and first published in Japan in 1983). At the time of the game’s original release, most adventure games were played using a “command input” system, where the player was asked to type in text to decide the actions of their character. Free text input systems like these allowed players to feel a great deal of freedom. However, they did come with one common source of frustration: players knowing what action they wanted to perform but being unable to do so because they could not find the right wording. This problem was caused by the limitations of PC performance and NLP technology of the time.