The four parajikas (defeats) are rules entailing expulsion from the monastic Order (Sangha) for life. If a monk or nun breaks any one of the rules he/she is automatically 'defeated' in the holy life and falls from monkhood immediately. He is not allowed to become a monk again in his/her lifetime. Intention is necessary in all these four cases to constitute an offence. The four parajikas for bhikkus are: 1. Sexual intercourse, that is, any voluntary sexual interaction between a bhikkhu or bhikkhuni and a living being. (from the Vinaya Pitaka)