History of MOBA (AOS) Games — From Aeon of Strife to LoL
What MOBA and AOS mean and how the genre grew from the StarCraft map Aeon of Strife to DotA, League of Legends, Dota 2, and mobile, plus key design traits.
There's a genre that people in Korea call "AOS games." Elsewhere, it's usually called MOBA (Multiplayer Online Battle Arena). Two teams each control one hero per player, fight along three lanes, and the team that first destroys the core building in the enemy base wins. League of Legends and Dota 2 are the best-known examples.
This genre wasn't planned and built by a company from the start. It began with custom maps, so-called "use maps," that fans made with the map editors of StarCraft and Warcraft III. In this post, we trace step by step how a single custom map became the world's biggest esports genre.
What Are MOBA and AOS?
MOBA is a subgenre that branched off from real-time strategy (RTS) games. A typical match looks like this:
- Usually, two teams of five players compete.
- Each player controls just one powerful character, called a "hero" or "champion."
- Weak computer-controlled units called "minions" periodically spawn from each base and march along set paths (lanes) toward the enemy side.
- There are usually three lanes (top, middle, and bottom), and between the lanes is the "jungle," home to neutral monsters.
- Each lane has defensive towers that attack automatically.
- You level up with experience to strengthen your skills and buy items with gold to grow stronger.
- The first team to destroy the core building of the enemy base (the Nexus in LoL, the Ancient in Dota) wins.
You can think of it as RTS with base building and unit production removed, focusing instead on the growth of a single hero and battles between teams.
The genre has had many names. "AOS," widely used in Korea, comes from the initials of Aeon of Strife, the StarCraft custom map considered the origin of the genre. The term "MOBA" was first used by Riot Games to describe the genre of League of Legends. Valve called Dota 2 an "action real-time strategy (ARTS)" game, and Blizzard introduced Heroes of the Storm as a "hero brawler."
Earlier Attempts: Herzog Zwei and Future Cop
The game often mentioned as a distant ancestor of the MOBA is Herzog Zwei (1989) for the Mega Drive. Players on two sides each directly controlled a single command unit while fighting, and it's also mentioned as a game that inspired the developers of Warcraft and StarCraft. The "Precinct Assault" mode of Future Cop: LAPD (1998) also involved fighting alongside automatically spawned allied units, so depending on the definition, it's sometimes considered an early MOBA.
Origins: The StarCraft Custom Map Aeon of Strife
In 1998, Blizzard released the map editing tool "StarEdit" along with StarCraft. With this tool, players could create maps with rules completely different from the original game. Among them, Aeon of Strife, made by Nick Taijeron, who went by the name "Gunner_4_ever," became hugely popular.
In this map, players controlled a single powerful hero unit and fought along three lanes guarded by defensive towers. Four players teamed up to face a computer-controlled side that was initially stronger. Heroes in early versions had no special abilities; instead, you upgraded weapons and armor with gold. The skeleton of the genre (one hero, three lanes, towers, and gold-based upgrades) was already there.
The 2000s: Warcraft III and DotA
In 2002, Blizzard released Warcraft III: Reign of Chaos along with a more powerful "World Editor." Both the MOBA and tower defense subgenres took full shape in this editor's community.
A modder named "Eul" made a map that ported Aeon of Strife to Warcraft III and named it Defense of the Ancients (DotA). When Eul soon stopped working on it, many people made various maps based on DotA.
After the expansion The Frozen Throne came out in 2003, a creator named "Meian" made DotA Allstars, which gathered heroes from multiple versions into one. A few months later, the map was taken over by Steve Feak, who went by "Guinsoo," and in his hands it became the defining map of the genre. Later, stewardship passed to "IceFrog." IceFrog continued making major changes that added depth to the game, and these were well received by the community. DotA was also adopted as an event at tournaments such as BlizzCon and the World Cyber Games (WCG).
DotA is credited with keeping the broad framework of RTS while focusing on teamwork, cooperation, and tactics rather than so-called "click battles" that favor people with fast hands.
Key Titles at a Glance
| Year | Game | Developer | Significance |
|---|---|---|---|
| 1989 | Herzog Zwei | Technosoft | Pioneering format of fighting with a single command unit |
| 1998 onward | Aeon of Strife | Nick Taijeron (StarCraft custom map) | Prototype of heroes, three lanes, and towers; origin of "AOS" |
| 2003 | DotA Allstars | Meian, Guinsoo, IceFrog, and others | Warcraft III map that established the genre's core rules |
| 2009 | League of Legends | Riot Games | Popularized the genre with a free model; established the name MOBA |
| 2010 | Heroes of Newerth | S2 Games | Brought the DotA feel to a standalone game |
| 2013 | Dota 2 | Valve | Official successor to DotA; The International |
| 2014 | Smite | Hi-Rez Studios | Third-person MOBA |
| 2015 | Heroes of the Storm | Blizzard | All-star cast of Blizzard characters; shared team levels |
| 2015 | Honor of Kings | TiMi Studio (Tencent) | The leading mobile MOBA |
Becoming Commercial: League of Legends and Dota 2
Around 2008, DotA's popularity attracted commercial interest. But because DotA was tied to Warcraft III, several companies began making "DotA-style" games independently. Gas Powered Games' Demigod (2009) is considered the first standalone commercial game.
League of Legends (2009)
Riot Games' first title, League of Legends, officially launched in North America on October 27, 2009. Steve Feak, who had led DotA Allstars, took part in its early design. It was free to play from the start and made money by selling cosmetic elements such as champions and skins. It launched in Korea in December 2011.
League of Legends is now the world's biggest esports title. After regional leagues, the "League of Legends World Championship" is held every year, and the 2019 final recorded a peak of 44 million concurrent viewers. It has also expanded into content beyond the game, such as the animated series Arcane and music from the virtual group K/DA.
Dota 2 (2013)
In 2009, Valve hired IceFrog and put him in charge of developing DotA's successor. It announced Dota 2 in 2010 and, after a trademark dispute with Blizzard, reached a settlement in 2012. Blizzard developed its own separate game and released it as Heroes of the Storm.
Dota 2 was officially released on Steam in July 2013, and all heroes are available for free from the start. In August 2011 at Gamescom, Valve invited 16 top DotA teams to a tournament, which became the annual "The International." Starting in 2013, it adopted a method of adding a portion of in-game item sales revenue to the prize pool, and the prize pool for the 2021 tournament reached $40 million.
Design Traits: What Makes MOBAs Special
- Focus on a single hero: Instead of managing many units as in RTS, you master one character in depth. This lowers the barrier to entry, while precision in using abilities still separates players by skill.
- Growth from scratch each match: Levels and items reset every match. Since every match starts on equal terms, competitive fairness is maintained.
- Division of roles: Roles are split among players who take lanes, players who roam the jungle, supports who help teammates, and so on, making team composition central to strategy.
- Many characters and matchups: Like fighting games, there are dozens to hundreds of heroes with different strengths and weaknesses, so strategy begins at the pick phase.
- A battle for the map and vision: Map control through jungle monsters, towers, and securing vision has a big impact on the outcome.
- Free to play with cosmetic sales: The leading MOBAs are funded by selling cosmetic elements that don't affect abilities.
On the other hand, the fact that a single match takes tens of minutes, and that one teammate leaving or behaving badly affects the whole match, is considered a long-standing challenge of the genre. Toxicity between League of Legends players has been pointed out from the early days, and Riot has tried various countermeasures.
MOBAs Today
In the late 2010s, many companies released new MOBAs following the success of League of Legends and Dota 2. However, many games, such as EA's Dawngate and Epic Games' Paragon, shut down around their official launch. Players were concentrated in the already established games, making it hard for new games to attract people.
Where growth has stood out is mobile. TiMi Studio's (Tencent) Honor of Kings (2015) became hugely popular in China and was also released internationally as Arena of Valor. In 2021, Pokémon Unite, the first MOBA in the Pokémon series, came out, and Riot also released League of Legends: Wild Rift for mobile and console. In 2024, Valve revealed Deadlock, a new third-person MOBA.
MOBAs have also drawn attention in research. In 2019, "OpenAI Five," an AI built by OpenAI, beat OG, the reigning The International champions at the time, in Dota 2 with restricted rules. It showed that MOBAs, which require many variables and team cooperation, are a difficult challenge for AI as well.
The small experiment that began as a StarCraft custom map became, in about 20 years, a genre with countless pro players and tournaments in large arenas. The history of MOBAs is one of the best examples of how player-made content can change the direction of the entire game industry.