Son of Subala, who was the king of Gāndhāra (Gandhara), and brother of Śakuni (Shakuni). This brother-in-law of Dhṛtarāṣṭra (Dhritarashtra) was seen for the first time in the Rājasūya yajña (Rajasuya yajna) of Yudhiṣṭhira (Yudhishthira).  It has been seen that the name of Acala’s other brother Vṛṣaka (Vrishaka) was always uttered along with that of Acala’s— acalo vṛṣakeśchaiva or vṛṣakācalau. This is how they have been referred to almost everywhere. In Rājasūya yajña they were also present in Indraprastha along with the invited Subala.