Dota 2 is a free-to-play multiplayer online battle arena game developed and published by Valve Corporation. It is the stand-alone sequel to Defense of the Ancients, a community-created mod for Blizzard's Warcraft III and its expansion pack The Frozen Throne. The game is played in matches between two teams of five, with each team occupying and defending their own separate base on the map. Each player independently controls a powerful "hero", who all have unique abilities and styles of play. During a match, a player and their team collect experience points and items for their heroes to fight through the opposing team's heroes and other defenses. A team wins by being the first to destroy a large structure located in the opposing team's base, called the "Ancient".
Despite some criticism of its steep learning curve and complexity, the game was praised for its rewarding gameplay, production quality, and faithfulness to its predecessor. Since its release, Dota 2 has been the most played game on Steam and allows for the creation of custom game modes, maps, and hero cosmetics, which are uploaded to Steam Workshop. Dota 2 has a widespread and active competitive scene, with teams from across the world playing professionally in various leagues and tournaments. Premium tournaments often have prize pools totaling millions of dollars, the highest of any eSport.
Dota 2 is a MOBA game in which two teams of five compete to collectively destroy a large structure defended by the opposing team called the "Ancient" whilst defending their own. Ten players each control one of the game's 113 playable "heroes", each having their own design, benefits, and weaknesses. Heroes are divided into two primary roles: the "carry" and "support". Carries or "cores" begin each match as weak and vulnerable, but are able to become more powerful later in the game, thus becoming able to "carry" their team to victory. Supports have abilities with more functionality and utility that provide assistance for their carries. Multiple game types exist, which mainly alter the way hero selection is handled.
All heroes have a basic damage-dealing attack, in addition to four unique abilities. Heroes begin each game with an experience level of one but are able to level up and become more powerful during the course of the game, up to a maximum level of 25. Whenever a hero gains experience, the player is able to unlock or improve an ability. The most powerful ability for each hero is called their 'ultimate', which requires them to be at level 6 to use. Activating an ability costs a hero some of their mana points, which slowly regenerates over time. Using an ability will also cause it to enter a cooldown phase. All heroes have three attributes: strength, intelligence, and agility, which affect health points, mana points, and attack speed respectively. Each hero has one primary attribute out of the three, which adds to their non-ability basic damage output when increased. Heroes also have an ability augmentation system known as "Talent Trees", which allow players further choices on how to develop their hero.
The two teams, the Radiant and Dire, occupy fortified bases in opposite corners of the map, divided in half by a crossable river and connected by three lanes guarded by defensive towers. A small group of weak creatures called 'creeps' travel predefined paths along the lanes and attack anything in their way. The map is also permanently covered for both teams in a fog of war, preventing a team from seeing the opposing team's heroes and creeps if they are not directly in sight of themselves or an allied unit. The map also features a day-night cycle, with some hero abilities and other game mechanics being altered depending on the time. Also present are hostile 'neutral creeps' that reside in camps, located in the area between the lanes called the 'jungle'. The most powerful neutral creep is named Roshan, who is a unique boss that may be defeated by either team to obtain a single-use item that allows near-instant resurrection if the hero holding it is killed. Roshan will respawn ten minutes after being killed and becomes progressively harder to kill as the match progresses over time. Runes, special items that spawn in set positions on the map every two minutes, offer heroes various powerful but temporary power-ups when collected.
In addition to having abilities becoming stronger during the game, players can use gold buy items that provide their own special abilities. Gold is primarily obtained by killing enemy heroes, destroying enemy structures, and killing creeps.
Dota 2 received universal acclaim. The most frequently praised aspects of the game were its depth, delivery, and overall balance. Comparisons of Dota 2 to other MOBA games are commonplace, with the game's mechanics and business model often being directly compared with League of Legends and Heroes of the Storm. A common criticism was that the game maintains a steep learning curve that requires exceptional commitment to overcome. Even then, Dota 2 won a lot of awards throughout the years following its release and has become prevalent in eSports.