[3] The plea prevents inconsistent decisions and the reopening of litigation.
[3] The limitations of these pleas have been circumscribed by various legal cases and appeals.
[4] In England, Wales and Northern Ireland, significant changes were made by the Criminal Justice Act 2003, by which an acquittal on a serious charge can be quashed and a retrial ordered, if there is "new and compelling evidence" against the acquitted person.
[5] In a civil case, a plea in bar alleges that circumstances exist that serve to block and defeat the plaintiff's case absolutely and entirely.
[6] Pleas in bar can include accord and satisfaction or the running of the statute of limitations.