Old Mahavic or Common Mahavic refers to a primitive stage in the development of the Mahavic languages, after the separation with Agyur but before the differentiation into the various remaining branches. It is unclear if it was a single language or a group of closely related and mutually intelligible languages that had derived independently from Proto-Mahavic. It is attested in a number of texts and inscriptions dating to the Ughmar Khaganate. Some limited quotations are believed to have been recorded much earlier in some other Parshitan states.
It is generally believed that the attested Old Mahavic language was a rather formal archaic register of the language, as some of the defining features that characterise the modern Mahavic languages are only rarely found despite its rather late attestation.
Old Mahavic had an unusual contrast of short and long (alternatively, lenis and fortis) obstruents even in word-initial position; compare kkoorı /kːoːrɯ/ and kuurı /kuːrɯ/. The precise realisation of these sounds are not clear: medially, the 'long' and 'short' consonants are reflected as geminates in West Mahavic but as single voiceless in East Mahavic (compare Old Mahavic kätte with Suenyi čätti /ˈtʃætti/ and Zindarri käte /ˈkæ.tə/), but initially both branches reflect them as short voiceless, although with subsequent glottalisation of the following vowel in East Mahavic (Old Mahavic kkoorı, Suenyi kuori /ˈkuo.ri/ and Zindarri qōri /ˈkoˤ.rɨ/). This effect has led some to suspect that the consonant had some sort of phonation instead of or in addition to length; suggested phonations include aspiration, glottalisation, stiff voice or pharyngealisation. Some evidence for this may be found in Ughmar loans: Old Ughmar aspirated stops are reflected as 'long' (e.g. korun /kʰɔrʊn/ as Old Mahavic kkorun) while unaspirated stops are reflected as 'short' (e.g. daḷun /taɭun/ as Old Mahavic talun). Sonorants may appear as geminates when medial but not initially, so they are not considered to be distinct phonemes.