There were two kinds of retrial systems in the Kamakura period: teichu, which was an appeal made based on a belief that the legal institution in question was unlawful; and osso, an appeal made based on a belief that the judgment contained a factual error.
鎌倉時代の再審制度には訴訟機関の不法を理由とした庭中と判決内容の事実誤認・過誤などを理由に起こす越訴の2つがあった。