Defense of the Ancients (DotA) is a mod for Warcraft III: Reign of Chaos and its expansion, The Frozen Throne.
The objective of the game is for each team to destroy their opponents' Ancient, a heavily guarded structure at the opposing corner of the map, which is based on the "Aeon of Strife" map for StarCraft. Players use powerful units known as heroes, and are assisted by allied teammates and AI-controlled fighters. As in role-playing games, players level up their heroes and use gold to buy equipment during the mission.
Heroes of Newerth was derived from the Warcraft III: The Frozen Throne custom map Defense of the Ancients.
Most game mechanics and many heroes in Heroes of Newerth are heavily based on Defense of the Ancients. The additions that differentiate Heroes of Newerth from Defense of the Ancients are features independent from gameplay; such as tracking of individual statistics, in-game voice communication, GUI-streamlined hero selection, game reconnection, match making, player banlists, penalties for leaving and chat features.