Game mechanics often come "first" in the development phase, with a narrative being tacked on later. But when game mechanics become separated from story, the disjunct makes for a bad experience as players become impatient or disinterested. However many of the best games, from Shadow of the Colossus to Dark Souls, have mechanics that enhance the mood created by the story and the characters, and visa versa. Achieving that synthesis is key to the field of narrative design in video games.