Defense of the Ancients

Defense of the Ancients (commonly known as DotA) is a custom scenario for the real-time strategy game Warcraft III: Reign of Chaos and its expansion, Warcraft III: The Frozen Throne, based on the "Aeon of Strife" map for StarCraft. The objective of the scenario is for each team to destroy the opponents' Ancients, heavily guarded structures at opposing corners of the map. Players use powerful units known as heroes, and are assisted by allied heroes and AI-controlled fighters called creeps. As in role-playing games, players level up their heroes and use gold to buy equipment during the mission.

The scenario was developed with the "World Editor" of Warcraft III: Reign of Chaos, and was updated upon the release of its expansion, The Frozen Throne. There have been many variations of the original concept; the most popular being DotA Allstars, which eventually was simplified to DotA with the release of version 6.68. This specific scenario has been maintained by several authors during development, with the current publicly anonymous developer known as "IceFrog" developing the game since 2005.

Since its original release, DotA has become a feature at several worldwide tournaments, including Blizzard Entertainment's BlizzCon and the Asian World Cyber Games, as well as the Cyberathlete Amateur and CyberEvolution leagues; Gamasutra declared that DotA was perhaps the most popular "free, non-supported game mod in the world". Valve Corporation is currently developing a sequel, Dota 2.

Gameplay
Defense of the Ancients pits two teams of players against each other: the Sentinel and the Scourge. Players on the Sentinel team are based at the southwest corner of the map, and those on the Scourge team are based at the northeast corner. Each base is defended by towers and waves of units which guard the main paths leading to their base. In the center of each base is the "Ancient", a building that must be destroyed to win the game.

Each human player controls one Hero, a powerful unit with unique abilities. In DotA, players on each side choose one of 110 heroes, each with different abilities and tactical advantages over other heroes. The scenario is highly team-oriented; it is difficult for one player to carry the team to victory alone. Defense of the Ancients allows up to ten players in a five-versus-five format and an additional two slots for referees or observers, often with an equal number of players on each side.

Because the gameplay revolves around strengthening individual heroes, it does not require one to focus on resource management and base-building, unlike most traditional real-time strategy games. Killing computer-controlled or neutral units earns the player experience points; when enough experience is accumulated, the player gains a level. Leveling up improves the hero's toughness and the damage it can inflict, and allows players to upgrade their spells or skills. In addition to accumulating experience, players also manage a single resource: gold. The typical resource-gathering of Warcraft III is replaced by a combat-oriented money system; in addition to a small periodic income, heroes earn gold by killing hostile units, base structures, and enemy heroes. This has caused emphasis on a technique called "last-hitting," which is when the player attacks a hostile unit when "its hit points are low enough to kill it with one blow". Using gold, players buy items to strengthen their hero and gain abilities; certain items can be combined with recipes to create more powerful items. Buying items that suit one's hero is an important tactical element of the scenario. Item choice also affects play style, as any given item may increase one statistic (for example, attack per minute) while leaving another (damage per attack) unchanged.

DotA offers a variety of game modes, selected by the game host at the beginning of the match. The game modes dictate the difficulty of the scenario, as well as whether people can choose their hero or are assigned one randomly. Many game modes can be combined (for example, an easy difficulty level and a random hero pick), allowing more flexible options.

Development
Warcraft III is the third title in the Warcraft series of real-time strategy games developed by Blizzard Entertainment. As with Warcraft II, Blizzard included a free "Warcraft III World Editor" in the game that allows players to create custom scenarios or "maps" for the game, which can be played online with other players through Battle.net. These custom scenarios can be simple terrain changes, which play like normal Warcraft games, or they can be entirely new game scenarios with custom objectives, units, items, and events, like Defense of the Ancients.

The first version of Defense of the Ancients was released in 2003 by a mapmaker under the alias of Eul who based the map on a previous StarCraft scenario known as "Aeon of Strife". After the release of Warcraft's expansion The Frozen Throne, which added new features to the World Editor, Eul did not update the scenario. Other mapmakers produced spinoffs that added new heroes, items, and features.

Among the DotA variants created in the wake of Eul's map, there was DotA Allstars, developed by modder Steve Feak (under the alias Guinsoo); this version would become today's dominant version of the map, simply known as Defense of the Ancients. Feak said when he began developing DotA Allstars, he had no idea how popular the game would eventually become; the emerging success of the gametype inspired him to design a new title around what he considered an emerging game genre. Feak added a recipe system for items so that player's equipment would scale as they grew more powerful, as well as a powerful boss character called Roshan (named after his bowling ball) who required an entire team to defeat.

Feak used a battle.net chat channel as a place for DotA players to congregate, but DotA Allstars had no official site for discussions and hosting. The leaders of the DotA Allstars clan, TDA, proposed that a dedicated web site be created to replace the various online alternatives that were infrequently updated or improperly maintained. TDA member Steve "Pendragon" Mescon created the former official community site, dota-allstars.com, on October 14, 2004.

Towards the end of his association with the map, Feak primarily worked on optimizing the map before handing over control to another developer after version 6.01. The new author, IceFrog, added new features, heroes, and fixes. Each release is accompanied by a changelog. IceFrog was at one time highly reclusive, refusing to give interviews; the only evidence of his authorship was the map maker's email account on the official website and the name branded on the game's loading screen. IceFrog now interacts with players through a personal blog where he answers common questions players have about him and about the game. He has also posted information about upcoming map releases, including previews of new heroes and items.

Defense of the Ancients is maintained via official forums. Users can post ideas for new heroes or items, some of which are added to the map. Players have contributed icons and hero descriptions and created the artwork displayed while the map loads, and suggestions for changes to existing heroes or items are taken seriously; IceFrog once changed a new hero less than two weeks after the new version of the map was released. Versions of the scenario where enemy heroes are controlled by artificial intelligences have also been released. Mescon continued to maintain dota-allstars.com, which by the end of IceFrog's affiliation in May 2009 had over 1,500,000 registered users and had received over one million unique visitors every month. Due to their separation, IceFrog announced that he would be further developing a new official site, playdota.com, while continuing game development; Mescon closed dota-allstars on July 22, 2010, citing dropping statistics and his new passion for League of Legends as the reason for its end.

Because Warcraft III custom games have none of the features designed to improve game quality (matchmaking players based on connection speed, etc.), various programs are used to maintain Defense of the Ancients. External tools ping player's locations, and games can be named to exclude geographic regions. Clans and committees such as TDA maintain their own official list of rules and regulations, and players can be kicked from matches by being placed on "banlists".

Reception and legacy
The popularity of Defense of the Ancients has increased over time. The scenario was featured by Computer Gaming World in a review of new maps and mods in Warcraft III. DotA Allstars became an important tournament scenario, starting with its prominence at the debut of Blizzard's BlizzCon convention in 2005. DotA Allstars was also featured in the Malaysia and Singapore World Cyber Games starting in 2005, and the World Cyber Games Asian Championships beginning with the 2006 season. Defense of the Ancients was included in the game lineup for the internationally recognized Cyberathlete Amateur League and CyberEvolution leagues. Additionally, the scenario appeared in Electronic Sports World Cup (ESWC) 2008; Oliver Paradis, ESWC's competition manager, noted that the high level of community support behind the scenario, as well as its worldwide appeal, were among the reasons it was chosen.

The scenario is popular in many parts of the world; in the Philippines and Thailand, it is played as much as the game Counter-Strike. It is also popular in Sweden and other Northern European countries, where the Defense of the Ancients-inspired song Vi sitter i Ventrilo och spelar DotA by Swedish musician Basshunter reached the European 2006 charts at #116 and cracked the top ten Singles Charts in Sweden, Norway, and Finland. LAN tournaments are a major part of worldwide play, including tournaments in Sweden and Russia; however, due to a lack of LAN tournaments and championships in North America, several teams disbanded. Blizzard points to DotA as an example of what dedicated mapmakers can create using developer's tools.

In June 2008, Michael Walbridge, writing for Gamasutra, stated that DotA "is likely the most popular and most-discussed free, non-supported game mod in the world". In pointing to the strong community built around the game, Walbridge stated that DotA shows it is much easier for a community game to be maintained by the community, and this is one of the maps' greatest strengths. Former game journalist Luke Smith called DotA "the ultimate RTS".

Defense of the Ancients has been credited as one of the influences for the 2009 Gas Powered Games title Demigod, with the video game publication GameSpy noting the game's premise revolved around aspiring gods "[playing] DotA in real life". Guinsoo went on to apply many of the mechanics and lessons he learned from Defense of the Ancients to the Riot Games title League of Legends. Other "DotA clones" include S2 Games' Heroes of Newerth. Blizzard Entertainment is also developing a free mod for StarCraft II: Heart of the Swarm entitled Blizzard DOTA, featuring an array of heroes from Blizzard's franchises.

Sequel
In October 2009, IceFrog was hired by Valve Corporation, leading a team in a project that he described as "great news for DotA fans". Valve filed the trademark for "Dota" in August 2010, leading to Steve Mescon to file a counter application of trademark for the phrase "Defense of the Ancients", on behalf of DotA-Allstars, LLC., in order to "protect the work that dozens of authors have done to create the game". Dota 2 was officially announced by Valve in October 2010.