This chapter first examines a number of Sanskrit terms equivalent to the word ritual. It then discusses and defines ritual based on four formal components that are also important for understanding legal procedures: (i) framing, including causal inducement and ceremonial decision (intentio solemnis, e.g., saṃkalpa); (ii) formality, with notions of repetitiveness, publicity, variation, and performativity; (iii) modality differentiation between individual implications (individualitas), social implications (societas), and transcending or elevating qualities (religio, Skt. apūrva); and (iv) transformation and confirmation of identity, role, status, or authority of the main participant(s). Focusing on paradigmatic rituals such as sacrifice (yajña, iṣṭi), life-cycle rituals (saṃskāra), and worship (pūjā), it also analyses various theories on ritual, for example, its structure and grammar, the meaning (-lessness) of rituals, or the Pūrvamīmāṃsā theory of ritual.