Feigned madness is acted madness, used in modern times to try to avoid punishment in a court of law, so called insanity defense. It could also be used to divert suspicion in advance of an act of revenge. Examples of this are Shakespeare's Hamlet, who feigns madness in order to speak freely, Lucius Junius Brutus, who feigned madness until the time when he was able to drive the people to insurrection, and David, who feigned madness in order to escape from King Achish.

In all of the above examples, the apparent madness makes people ignore the person in question, considering them useless and/or harmless rather than anything else, thus enabling the person to escape any plans to kill, imprison or otherwise inflict unpleasantness upon them by an enemy.

References

• David and king Achish
• Lucius Junius Brutus
• Hamlet