Fan Casting Not a Game in Sort by Tropes

A Stock Phrase used on characters frivolous in the face of a Matter of Life and Death. "This isn't a game." or "We are not playing a game." (Or sometimes "We are not playing.") Sometimes even when it is a game, but the stakes are too high to treat it as one, such as the second type of Serious Business; alternatively, the character may point that "This is serious," generally with an enumeration of the consequences. (With the first type of Serious Business, use of this is a characterization trope: the character really is that out of touch with reality.)