Ah, the wonderful history of Dota. This is an article that I've had a number of people request from me, and one that I was dreading to write. "Why, my humble writer," I hear you ask, "what could possibly be terrifying about writing a history article?"
The answer is everything. Dota's history, as with that of many popular mods, is rife with arguments over who is owed credit for what pieces, who stole what, and what came from where. Nobody expected that, in the decade after the earliest Dota-like games, there would be development companies spending millions of dollars to create the purest and most fun form of the genre. Very simply, no one thought to record what happened when. The best we can do now is look backwards and try to piece together the ancestry of the game that reached its current apogee in Dota 2.
The Early Days: Starcraft
In 1998, Blizzard Entertainment released what would come to be the top selling PC game of all time, Starcraft. Included with this game were a host of map editing and creation tools called StarEdit. StarEdit was truly a fantastically fun piece of software. Unlike other RTS games of the time that came with map creators, StarEdit contained a deep and complicated piece of scripting that it called Triggers. This, combined with the then-unknown amount of customization of units allowed in the engine meant that it was a playground for anyone that wanted their hand at making a fun UMS (Use Map Settings) map, without having to learn the ins and outs of things like the Doom or the Quake engines. Later that year, with the release of Brood War, the editor became even more powerful, and people learned how to unlock StarEdit's potential.
This creativity and freedom lead to a number of incredible maps, which used such odd engine behaviors as unit stacking in fog, or creating unit-location triggers, which weren't available by default. One of the maps of this era, and our first stop in the history of Dota, is Aeon of Strife. Aeon was a fantastically odd map for Starcraft vets: you controlled only one powerful unit hero, fighting amidst ai-controlled enemies in three lanes. Sound familiar? Aeon of Strife focused much more on towers than modern Dota ever has, with very little terrain outside of the lanes. It also (at first) boasted a roster of only 8 hero units, without any particular special abilities. You spent gold on armor or weapon upgrades. Later versions, however, added some Skills which could be triggered by dropping the appropriate 'activator' unit from a dropship in a secluded corner of the map. Still, you bought the ability units with gold, and there was no real concept of levels beyond how many weapon and armor upgrade you had bought.
The Ancients Arise: Warcraft III
In 2003, the game changed. Literally. Blizzard released Warcraft III, along with its editing tools, and modders went crazy. It's hard to describe this period of time, though I know many of you reading went through it with me. Towards the tail end of SC:BW, UMS maps had become prolific and fun, with games like Lurker Defense and Zone Control. Warcraft III's editor allowed map creators to take it to the next level, and the scene exploded. Other WC3 map types such as tower defense spawned genres of their own, and in the midst of this, a modder by the name of Eul began work trying to convert Aeon of Strife into the new engine. This map was called Defense of the Ancients, or DotA.
Now instead of 6 players and 2 AIs per map, Eul could have 5 players and an AI on each team. The built in Hero and Skill support allowed each character more depth and interesting progression than Starcraft maps could ever hope to contain. That being said, the early DotA maps were... shall we say Alpha versions? You can check out some of them at dotautilities, but be aware that many probably don't work with the newest WC3 patch, and they are extremely rough in places.
A Small Schism
After a time, Eul left the DotA development scene for a time. Tons of other modders stepped in, creating dozens of various DotA versions, containing characters from various television shows, video games, and personal creations. There was no clear successor to Eul's DotA, and for a good amount of time you ended up downloading a new map with every new game you joined.
Roster Changes: Guinsoo and Pendragon
At some point in 2004-2005, a modder named Guinsoo came to the scene and created his own version of DotA, very closely using the map from Eul's, but taking the most interesting heroes from various other versions. He called this "DotA: Allstars," and marks the start of what we think of today as DotA. For one, Guinsoo added a new mechanic that would come to define DotA's items: recipes. Built off of TP scrolls, they didn't do anything on their own, but would be consumed to create a new item if the proper components were in your inventory. Even more clever, Guinsoo soon figured out how to create recipes that could auto complete.
These new recipes cost 1 Wood resource, which was impossible to obtain. However, getting the proper ingredients would make the item instantly appear in your inventory (when in range of a shop at first, though later changed to work anywhere).
Also around this time, as Allstars was gaining popularity, an enthusiastic player by the name of Pendragon created a set of forums which would define the dota community for almost 5 years. The Dota-Allstars forum became the main medium of communication between Guinsoo and the community, and contained everything from in-depth mechanics guides to player-created hero and item suggestions, and the organizations of the first real DotA tournaments.
The Creator Divine: Icefrog
Guinsoo maintained the DotA: Allstars map for over two years, before handing it off to a modder you may have heard of: Icefrog! It's hard to describe what DotA was like during this transitional period. Icefrog is some sort of DotA savant. He put the game through such drastic changes that many thought the community would just shatter. It didn't however, and with each new iteration, from Pudge to Buybacks to Ward Vision to Channeling changes, the game's community grew by leaps and bounds.
Icefrog also began to try to perfect the map, creating many strange alterations that helped to make the map much more interesting to play than previously. These, combined with his carefully thought out balance tweaks, created a thriving competitive community. Numbers of users on the Dota-Allstars forum were thought to peak at over a million, with Icefrog claiming at one time that a newly released DotA map could reach over 4 million downloads from individual IPs.