The name given to a set of rules to be observed by members of the Buddhist Order. The rules regulate the behaviour of the members of the Order towards one another in respect of clothes, dwellings, furniture, etc., held in common. Transgression of the four pārājikas entails permanent expulsion, of the thirteen saṅghādisesas entails suspension, of the thirty nissaggiya pācittiya entails forfeiture of some possession with confession, while the rest entail a confession only.
The texts speak of a set of 150 rules, AN.i.231–232 but the current list in Pali has 227. Perhaps the sekhiya were not originally recited.
The Pātimokkha is not included in the extant Buddhist Canon. The rules are included, in the Sutta Vibhaṅga, which contains besides the rules themselves, an old Commentary explaining them and a new Commentary containing further supplementary information concerning them. The rules are divided into two parts: one for the monks and the other for the nuns.
The rules were recited at the gatherings of members of the Order Vin.i.101–136 in their respective districts on uposatha days, the fourteenth and fifteenth days of the month. Each section of the rules is recited and, at the end of such recital, the reciter asks the members of the Order who are present if any one of them has infringed any of the rules. Silence implies absence of guilt. This practice of interrupting the recital seems to have been changed later Vin.ii.240ff. even though the old formula, asking the members to speak, continued as a part of the recital.
The word pātimokkha is variously explained, the oldest explanation being that the observance of the rules is the face (mukhaṃ), the chief (pamukhaṃ) of good qualities.