Only Tri-Varṇa has the right to perform Vedic Sacrifice

Though the sacrifice is the worship of God, yet all are not entitled to perform Vedic sacrifice. The person, who is married, who is learned in Vedic lores, or who has faith in Vedic sacrifice has right to perform Vedic sacrifice. In keeping with the old social system, the Śudras, who formed the bulk of the human population of ancient India, did not have right to Vedic studies or to perform Vedic sacrifice. But according to modern sociology, the Śudras face no obstacle to study Vedas or to perform Vedic sacrifice. Again, the person though belonging to traivarṇika class, may lose his hereditary Vedic right at his own sweet will if he has no faith in Vedas. Hence in the modern days, we presume, nobody has any misgiving regarding the right to sacrifice.

To Vedic Aryans, sacrifices were the best works. By performing the sacrifice, man achieved all comprehensive welfare in his life. Everyman has desire to accomplish his own well beings; hence it is natural that everybody has right to perform sacrifice; but in reality all were not entitled to perform Vedic sacrifices. It is not definitely ascertained as to whether, in the beginning of the Vedic age when the class-distinction was not rigidly applicable, any difference was there in the Vedic society regarding right to perform sacrifice. But in the later period when the four classes viz. Brāhmaṇa, Kṣatriya, Vaiśya and Śudra were clearly differentiated in the society, then the law makers debarred Śudras from the right to sacrifice. Women also did not perform sacrifice separately; but they along with their husbands used to participate in the sacrifice in some definite tasks. Therefore, only the three upper classes, Brāhmaṇa, ḳsatriya, and Vaiśya have the right to perform sacrifices. The person who was unmarried and not learned in Vedic lores also has no right to Vedic sacrifice