Game Jargon Definition: “Critical Failure”
Critical Failure (noun) - crit · i · cal fail · ure. /ˈkridək(ə)l ˈfālyər/
Within the context of role-playing games, a critical failure is a failure brought about by an exceptionally poor dice roll that not only results in the lack of accomplishment of the task attempted by a character, but has additional negative effects for the character and possibly the other characters in the adventuring party. This is due not just to a failed attempt at a given task, but an exceptionally poorly executed attempt of said task.
In role-playing games that employ dice systems, critical failures are often brought about by rolling a 1 on a 20-sided die, or by the lowest possible natural roll on the dice being used. There are very few role-playing game systems with official rolls for a critical failure. But where they exist, these have traditionally been house rules that have been developed and used by gaming groups.
There tends to be a certain amount of humor around critical failures in the role-playing game community. While attempting to make an attack against an enemy, when a critical failure occurs, the game master will very often narrate that the character making a swing with a sword ended up over swinging and injuring themself, regardless of the absurdity of such a thing actually occurring.
Because critical failure mechanics have become common in role-playing games, the term “critical failure” has a number of synonyms that have been used over the years, including “critical miss,” “fumble,” “botched,” “flub,” “mishap,” and “infernal intervention,” to name a few.