Defense of the Ancients (here on out DoTA) is a custom map made for Warcraft 3 (first Reign of Chaos, then The Frozen Throne) which has been developed to the point of being arguably distinct enough to be a game of it's own. The map still requires Warcraft 3 ROC and TFT to play, but the game-play is so far from that of the ordinary play of Warcraft 3 that people talk about it as if it were its own entity.

The objective of the game is fairly simple: Destroy the single building in the opponents' base. To do this, your team has the ability to pick up to 5 different heroes, each one controlled by a different player, and use these heroes to coordinate attacks on your opponents. Between your team and the opponents' single building stands 5 other players, each with their own heroes, a fairly sizeable base, a series of defence towers, and an ever spawning army of "creeps". Don't be fooled, you can't simply waltz into their base and take down the single building, you have to unlock the vulnerability of each building before it.

To start unlocking the vulnerability of buildings you need to destroy the defending towers in order, starting with the ones nearest to your own towers, leading back into their base. Once you destroy all the towers in a particular "lane" you unlock the buildings which spawn creeps for that lane for the opponent, allowing those buildings to be destroyed. Once both unit producing buildings are down, your creeps become stronger for that lane and give you a greater advantage. Once you start moving into their base and taking out at least one lane, the two defending towers covering the single objective building (which by the way are stronger than the earlier defending towers you faced) are now vulnerable. Kill those two towers, and you can now finally attack your final objective. Once this building is destroyed, you instantly win the game.

Sounds easy, doesn't it? Well, don't forget about those 5 other players on the other team. They're not only out to stop you, but also out to destroy your equivalent building in the identical manner too. They wont hesitate to kill you, given the chance, so work hard to be strong and show no vulnerability.

The hero combinations in DoTA are nearly endless. With a total hero count of 93 to pick from (as of v6.60b) the combinations for your team and your opponent are nearly unpredictable. This results in an extremely high replay value, as you are almost guaranteed to not get the same game again for a very long time. With these combinations, team coordination plays a huge role, as you not only need to play wisely but you need to choose your hero wisely too. Properly coordinated teams will decide who is going what hero in advance in order to control how they will engage the opposing team. Different team designs result in different objectives. Some focus on Area of Effect damage (AoE), some focus on Stun controlling, some on other objectives. The primary goal of coordinating a proper selection of heroes is to choose heroes that compliment each other when in combat together, and in turn grant a drastic advantage over the opposing team when utilized together.

To add further variety to the game-play, the inventory selection is almost as equally massive as the hero selection. The items start off simple, providing simple benefits, and through a recipe system result in a very elaborate web of combinations of items. These combinations provide huge variety in how your hero's capabilities respond, not all positively however if you choose poorly. Choosing wisely can grant you drastic advantages, but choosing poorly can result in mediocre advantages to no advantage. Despite this, there are plenty of variations in which a hero can choose items and still have drastic advantages, playing to different strengths between different combinations. These combinations of items can take an entire game length to properly coordinate and set up, some even not possible unless you play extended games, which go on beyond the average game time.

All these elements combine to form a custom map that has been in constant development since shortly after the release of Warcraft 3, back in 2002. Since release, the interest in DoTA has grown steadily, only recently resulting in enough interest to have tournaments held for DoTA internationally. New players will find the game to have a steep learning curve, but once such players start to understand the flow of the game, they begin realizing the rewarding elements of DoTA. DoTA has arguably one of the most unforgiving game-play designs of any type of game, resulting in punishment for those who make mistakes, but result in great reward for those who take wise chances and succeed.