To Mateas and Stern, creators of "Façade" and "The Party", interactive storytelling is best understood as interactive theater, in that its goal is dramatic meaning rather than fun. It was Chris Crawford who coined the term interactive storytelling in the 1990s, arguing that IS is not a video game with a narrative, and that a game and IS cannot be combined successfully. Because of limited technology and the amount of work required, it is still difficult to combine a robust interactive storytelling system and a game engine without detracting from the effectiveness of both.