The wilful misconduct represents the misleading of a person by another person by using evil means to cause him/her to clinch a legal act to which he/she would not have consented otherwise.
Similarly to error, the wilful misconduct falsifies reality, but this false reality is caused by evil means by the other contracting party. Some authors define wilful misconduct as “an error caused” by the other contacting party.
The party whose consent was vitiated by wilful misconduct may request cancellation of the contract, even if the error which he/she was involved in was not essential. The penalty is relative nullity of the legal act concluded, because the rule of law protects a private interest with the right of the wilful misconduct’s victim to claim damages, that is to say damages compensation to cover the loss suffered.
Being a relative nullity, it can only be invoked by the party whose consent was vitiated, the heirs having no active procedural standing to invoke the relative nullity because it is a personal action; they may continue the lawsuit if after initiating the action the victim of the wilful misconduct died.