Three main installments, as well as one online game, were published for the PlayStation 2 (PS2). Final Fantasy X (2001) introduced full 3D areas and voice acting to the series, and was the first to spawn a direct video game sequel (Final Fantasy X-2, published in 2003). The first massively multiplayer online role-playing game (MMORPG) in the series, Final Fantasy XI, was released on the PS2 and PC in 2002, and later on the Xbox 360. It introduced real-time battles instead of random encounters. Final Fantasy XII, published in 2006, also includes real-time battles in large, interconnected playfields. The game is also the first in the main series to utilize a world used in a previous game, namely the land of Ivalice, which had previously featured in Final Fantasy Tactics and Vagrant Story.
Magic is another common RPG element in the series. The method by which characters gain magic varies between installments, but is generally divided into classes organized by color: "White magic", which focuses on spells that assist teammates; "Black magic", which focuses on harming enemies; "Red magic", which is a combination of white and black magic, "Blue magic", which mimics enemy attacks; and "Green magic" which focuses on applying status effects to either allies or enemies. Other types of magic frequently appear such as "Time magic", focusing on the themes of time, space, and gravity; and "Summoning magic", which evokes legendary creatures to aid in battle and is a feature that has persisted since Final Fantasy III. Summoned creatures are often referred to by names like "Espers" or "Eidolons" and have been inspired by mythologies from Arabic, Hindu, Norse, and Greek cultures.