The legal principle where a duty – or ‘burden’ – is placed on a party in a court action to prove or disprove disputed facts before the court will make a judgment. It is the threshold that a party seeking to prove a fact in court must reach in order to have that fact legally established; that is, to convince a decision-maker in a trial (judge; jury) that one’s version of the facts is true. (In general, the threshold or level is ‘beyond reasonable doubt’ in a criminal dispute and ‘on the balance of probabilities’ for civil disputes).