Language recognition is not a new concept to video games - the first text adventures had to understand commands somehow. But researchers are trying to integrate it in more open-ended ways - allowing for dynamic conversations between players and characters.
BBC Radio profiled the efforts, lately highlighted in the game 221B, a movie adaptation of the recent Sherlock Holmes film. In it, players must interrogate witnesses and suspects to gain answers that advance the story.
"Rather than attempting to create an exhaustive list of possible questions and the appropriate response, the characters in the game are capable of making a 'fuzzy interpretation' of what is said to them," the BBC reports. "The intention is to remove the frustration, familiar to any who played the old text-based adventure games, of having to guess the right way of asking a question or giving an instruction."
Other games based on open-ended use of language, spoken or written, include Facade and, of course, Scribblenauts - and even Left 4 Dead. "Each of the characters has a set of voice samples which can trigger based on events, situations and other dialog lines," Rockstar's Alex Champandard said of L4D. "This results in completely emergent short conversations depending on the situation."
The BBC calls it one of "the last uncracked problems" in games design. It's a good read, especially for the humorous kicker paragraph.
AI Aims to Solve In-Game Chatter [BBC Radio]