Multi-player online battle arena video games

Multi-player online battle arena video games (MOBA), also known as action real-time strategy (ARTS), is a sub-genre of the real-time strategy (RTS) genre, in which often two teams of players compete with each other in discrete games, with each player controlling a single character through an RTS-style interface. It differs from traditional RTS games in that there is no unit construction and players control just one character. In this sense, it is a fusion of action games and real-time strategy games. The genre emphasizes cooperative team-play; players select and control one "hero", a powerful unit with various abilities and advantages to form a team's overall strategy. The objective is to destroy the opponents' main structure with the assistance of periodically spawned computer-controlled units that march towards the enemy's main structure via paths referred to as "lanes".

The genre traces its roots to Aeon of Strife (AoS), a custom map for StarCraft. Defense of the Ancients (DotA), a map based on Aeon of Strife for Warcraft III: Reign of Chaos and The Frozen Throne, was one of the first major MOBA titles.

History
An early predecessor to the genre was the 1989 game Herzog Zwei which is considered to be the progenitor of the modern real-time strategy genre. One key differences between Herzog Zwei and modern action RTS games is that Herzog Zwei allowed the player to command an army of units, while the modern genre features waves of uncontrolled units that spawn at set intervals. The Dynasty Warriors series could also be considered early MOBA games, starting with Dynasty Warriors 2 (1997).

The custom map Aeon of Strife for the real-time strategy game StarCraft is one of the earliest examples of the modern genre. It was followed by Defense of the Ancients, a custom scenario for Warcraft III that was heavily based on Aeon of Strife. The growing popularity of Defense of the Ancients led to the development of further custom maps as well as full stand-alone games. These games are sometimes referred to as "DotA-style", "DotA-esque", "DotA-clone" or "DotA-based", although were more commonly referred to as AoS's.

Minions is a game by The Casual Collective released in 2008 as a Web game using Flash.

Demigod, a video game developed by Gas Powered Games was the first released stand-alone title in the genre.

This was followed by Riot Games' League of Legends released in October 2009. Riot Games attempted to break away from the genre being known as "Dota" by coining its own marketing term, "Multiplayer Online Battle Arena" (MOBA).

In May 2010, S2 Games released Heroes of Newerth.

On 13 October 2010, Valve Corporation announced its official entry to the genre with a sequel to Defense of the Ancients entitled Dota 2. Valve referred to Dota 2 and similar games as "Action Real-Time Strategy" games.

At BlizzCon 2010, Activision Blizzard officially announced their entry to the genre with their Blizzard DOTA map for StarCraft II. Chris Sigaty, lead producer of Starcraft II, stated that Blizzard DOTA "is a take on the DOTA genre if you will. It gives you the opportunity to see some of the heroes we've made, we've made some heroes that are cross genre. Not just SC2 heroes, we've got some Diablo characters in the works, we've some Warcraft characters and StarCraft characters and they're fighting together." On May 11, 2012, Blizzard announced that the map would be named "Blizzard All-stars", after settling a trademark dispute with Valve over the usage of the DOTA trademark.