Final Fantasy X (ファイナルファンタジーX Fainaru Fantajī Ten) is a role-playing video game developed and published by Square (now Square Enix) as the tenth entry in the Final Fantasy series. Originally released in 2001 for Sony's PlayStation 2, the game was re-released as Final Fantasy X/X-2 HD Remaster for PlayStation 3 and PlayStation Vita in 2013, for PlayStation 4 in 2015 and for Microsoft Windows in 2016. The game marks the Final Fantasy series transition from entirely pre-rendered backdrops to fully three-dimensional areas, and is also the first in the series to feature voice acting. Final Fantasy X replaces the Active Time Battle (ATB) system with the "Conditional Turn-Based Battle" (CTB) system, and uses a new leveling system called the "Sphere Grid".