In the Vedic religion, Ṛta (/ɹ̩ta/; Sanskrit ऋत "order, rule; truth; logos") is the principle of natural order which regulates and coordinates the operation of the universe and everything within it. In the hymns of the Vedas, Ṛta is described as that which is ultimately responsible for the proper functioning of the natural, moral and sacrificial orders. Conceptually, it is closely allied to the injunctions and ordinances thought to uphold it, collectively referred to as Dharma, and the action of the individual in relation to those ordinances, referred to as Karma – two terms which eventually eclipsed Ṛta in importance as signifying natural, religious and moral order in later Hinduism. Sanskrit scholar Maurice Bloomfield referred to Ṛta as "one of the most important religious conceptions of the Rigveda, going on to note that, "from the point of view of the history of religious ideas we may, in fact we must, begin the history of Hindu religion at least with the history of this conception".
Vedic and its Avestan equivalent aṣ̌a both derive from Proto-Indo-Iranian *Hr̥tás "truth", which in turn continues Proto-Indo-European * "properly joined, right, true", from a presumed root *.
The derivative noun ṛta is defined as "fixed or settled order, rule, divine law or truth".
As Mahony (1998) notes the term can be translated as "that which has moved in a fitting manner". Although this meaning is not actually cited by authoritative Sanskrit dictionaries it is a regular derivation from the verbal root ṛ, "to move" with ta, the suffix which forms the past participle, so it can be regarded as the putative origin of the word. More abstractly, it is translated as "universal law" or "cosmic order", or simply as "truth". The latter meaning dominates in the Avestan cognate to Ṛta, aṣ̌a.
The proper Sanskrit pronunciation of the word is ṛta, the ṛ being a vocalic r, like that in pert or dirt, when pronounced with a rhotic r, e.g. as in American, followed by a short a.