Is a Muslim obligated to complete the Tarawih prayer after commencing it, or is it permissible for him to depart after praying as much as he wishes?

Tarawih prayer is a Sunnah (definition) and a supererogatory act; a Muslim has the choice between performing it or leaving it, though performing it is better. It is permissible to leave the Tarawih prayer before the worshipper completes it with the Imam, but it is better to remain with him until he departs, so that the worshipper is credited with the prayer of an entire night, as the Prophet, peace and blessings be upon him, said: "Whoever prays with the Imam until he departs, Allah will record for him the prayer of an entire night."