Despite experimenting with several nonlinear storytelling mechanisms in the 1990s, the game industry has largely returned to the practice of linear storytelling. Linear stories cost less time and money to develop, since there is only one fixed sequence of events and no major decisions to keep track of. For example, several games from the "Wing Commander" series offered a branching storyline, but eventually they were abandoned as too expensive. Nonlinear stories increase the chances for bugs or absurdities if they are not tested properly, although they do provide greater player freedom. Some players have also responded negatively to branching stories because it is hard and tedious for them to experience the "full value" of all the game's content. As a compromise between linear and branching stories, there are also games where stories split into branches and then fold back into a single storyline. In these stories, the plot will branch, but then converge upon some inevitable event, giving the impression of a Nonlinear gameplay through the use of nonlinear narrative, without the use of interactive narratives. This is typically used in many graphic adventure games.