Sacrifices are normally divided into iṣṭi, paśu and soma. There are seven soma sacrifices which are part of 48 saṃskārs. They are:
The soma sacrifices are grouped according to their duration. The sacrifices that are completed in one day are called 'ekāha' sacrifices. The sacrifices which are completed in more than one day up to twelve days is called 'ahīna' and sacrifices that are performed for more than twelve days are called 'sattra'.
Ekena hyahā yogādekāhatvaṃ| dvyadibhirahīnatvaṃ pragdvādaśāt|[1]
Agniṣṭoma[edit]
Agniṣṭoma is the archtype[2] sacrifice of all soma sacrifices. Agniṣṭoma is an integral part of jyotiṣṭoma so much that both are identified interchangeably. Agniṣṭoma is so called because agni is mainly praised in the sacrifice. It is to be performed in the vasanta ṛtu[3] every year.
Atyagniṣṭoma[edit]
Atyagniṣṭoma is a sacrifice similar to Agniṣṭoma with an addition of ṣoḍaśistotra.
Ukthya[edit]
Ukthya or Uktha is a modification to agniṣṭoma. In this sacrifice there are three more stotras, which are called as ukthya stotras and three ṣastras, which are called as ukthya stotras. The total number of stotras and śastras are a part of Ukthya which number upto fifteen each.
Śoḍaśī[edit]
In this sacrifice, there is an additional stotra and śastra, called ṣoḍaśi stotra in addition to the fifteen stotras and śastras of ukthya.
Atirātra[edit]
It is called so, because the sacrifice is not completed in one day, but only after the day and night. Hence it is called Atirātra. The sacrifice has 29 stotras and śastras.
Aptoryāma[edit]
This sacrifice is similar to Atirātra with additional four stotras and four śastras to 29 stotras and śastras, making them 33 in all.
Vājapeya[edit]
This is an independent sacrifice which is not similar to other soma sacrifices. This sacrifice has 17 stotras, 17 śastras, out of which 17th śastra is called vājapeya śāstra.