The Roman Ritual (Latin: Rituale Romanum) is one of the official ritual works of the Roman Rite of the Catholic Church. It contains all of the services which may be performed by a priest or deacon which are not contained within either the Missale Romanum or the Breviarium Romanum. The book also contains some of the rites which are contained in only one of these books for convenience.
When first ritual functions books were written, the Sacramentary in the West and the Euchologion in the East, they contained all the priest's (and bishop's) part of whatever functions they performed, not only for the Mass or Divine Liturgy, but for all other sacraments, blessings, sacramentals, and rites of every kind as well.
The contents of the Ritual and Pontifical were in the Sacramentaries. In the Eastern Churches this state of things still to a great extent remains. In the West a further development led to the distinction of books, not according to the persons who use them, but according to the services for which they are used. The Missal, containing the whole Mass, succeeded by the Sacramentary. Some early Missals added other rites, for the convenience of the priest or bishop; but on the whole this later arrangement involved the need of other books to supply the non-Eucharistic functions of the Sacramentary. These books, when they appeared, were the predecessors of the Pontifical and Ritual. The bishop's functions (ordination, confirmation, et cetera) filled the Pontifical, the priest's offices (baptism, penance, matrimony, extreme unction, etc.) were contained in a great variety of little handbooks, finally replaced by the Ritual.