Dota 2 is a multiplayer
online battle arena video game, the stand-alone sequel to the Defense of the Ancients (DotA) Warcraft III: Reign of Chaos and The Frozen Throne mod. Developed by Valve Corporation, Dota 2 was released as a free-to-play title for Microsoft Windows, OS X, and Linux
in July 2013, concluding a Windows-only public beta testing phase that began in 2011.
Dota 2 is
played in matches involving two teams of five players, each of which occupies a stronghold at a corner of the map. Each stronghold contains a building called the "Ancient", which the opposite team must destroy to win the match. Each player controls a character
called a "Hero", and focuses on leveling up, collecting gold, acquiring items, and fighting against the other team
to achieve victory.
Development of Dota 2 began in 2009 when IceFrog, lead designer of the DotA mod, was hired by Valve as lead designer. Dota 2 was praised by critics for its gameplay, production quality, and faithfulness to its predecessor, despite being criticized for its steep
learning curve. The game is the most actively played game on Steam, with daily peaks of over 900,000 concurrent players as of August 2015.