The rules of discipline first laid down by the Buddha are called Mþlapaññatti (the root regulation); those supplemented later are known as Anupaññatti. Together they are known as Sikkhæpadas, rules of discipline. The act of transgressing these rules of discipline, thereby incurring a penalty by the guilty bhikkhu, is called Æpatti, which means ‘reaching, committing’.

The offences for which penalties are laid down may be classified under seven categories depending on their nature:

(i) Pæræjika
(ii) Saµghædisesa
(iii) Thullaccaya
(iv) Pæcittiya
(v) Pæ¥idesanøya
(vi) Dukka¥a
(vii) Dubbhæsita.

An offence in the first category of offences, Pæræjika, is classified as a grave offence, garukæpatti, which is irremediable, atekicchæ and entails the falling off of the offender from bhikkhuhood.

An offence in the second category, Saµghædisesa, is also classified as a grave offence but it is remediable, satekicchæ. The offender is put on a probationary period of penance, during which he has to undertake certain difficult practices and after which he is rehabilitated by the Saµgha assembly.