ABSTRACT In Indian logic, Nigrahasthāna (fault) generally refers to the occasion of defeat in debates. The fundamental theme of Vādanyāya is to discuss the issue of fault in debates. Based on the standpoint of Buddhist logic, Dharmakīrti in Vādanyāya, starting from the argumentative structure and rules of Buddhism, creatively developed the theory of fault in his debate logic, which can also be seen as a revision of the theory of fault in the Nyāya school. Delving into the logic and culture of the Nyāya school, he critically analyzed and accepted various types of faults in the Nyāyan list of faults. Dharmakīrti’s thoughts about fault can be explored from four aspects: first, establishing the logical rationality of debate; second, innovating the classification criteria of faults; third, criticizing the theory of fault in the Nyāya school; and fourth, accepting the reasonable types of faults in the Nyāya school.