Partiality
As one might guess from the word itself, this is the opposite of impartiality, i.e., it is when a judge shows bias toward a party or the party’s attorney. As a legal claim, this is incredibly difficult to prove and generally not worth pursuing. Judges are presumed to be free of bias and prejudice, and a party challenging that must show specific facts that prove the bias, and it cannot be that the judge has ruled against that party. See also Judicial Bias.