Heroes of the Storm (HotS) is a multiplayer online battle arena video game developed and published by Blizzard Entertainment for Microsoft Windows and OS X. The game features heroes from Blizzard\'s franchises including Warcraft, Diablo, StarCraft, The Lost Vikings, and Overwatch. The game uses both free-to-play and freemium models and is supported by micropayments, which can be used to purchase heroes, visual alterations for the heroes in the game, and mounts. Blizzard does not call the game a \"multiplayer online battle arena\" or an \"action real-time strategy\" because they feel it is something different with a broader playstyle; they refer to it as an online \"hero brawler\".Heroes of the Storm revolves around online 5-versus-5 matches, operated through Blizzard\'s online gaming service Battle.net. Players can choose from three game modes, which include playing with/against computer-controlled heroes or other players. When players first start the game, they may play 6 heroes provided by the free hero rotation, a methodically selected list that changes weekly, but by using gold coins, the in-game source of wealth, or through microtransactions, they can gain permanent access to a hero. Four additional free hero slots are available to players who have reached level 15, rewarded progressively.As of March 2017, there are currently 64 heroes in the game, divided into 4 separate roles: Assassin (damage dealer and attacker), Warrior (damage absorber and bruiser), Support (healer and combat augmenter) and Specialist (siege, summoner and commander). Varian Wrynn from the Warcraft universe, added in November 2016, is the first \"multiclass\" hero; he can be either a Warrior or Assassin depending on his talent choices.Of the currently released maps, nine of the 12 have the standard three main lanes where players can fight, while the others have only two main lanes, but a separate objective-based area. Killing computer-controlled enemy/neutral units and the opposing side\'s heroes grants experience points, which are shared with the entire team. When a certain experience point threshold is reached for a team, every hero on that team levels up, acquiring slightly amplified powers and gaining a talent point upon reaching certain levels. Talent points allow players to customize and empower their hero\'s abilities and generally result in large increase in use. This leveling system emphasizes the importance of teamwork and planning, since a player\'s action can affect the whole team. Players can also mount different animals, such as horses, lizards, or unicorns, to increase their movement speed, automatically dismounting when dealing/receiving damage or using an ability. Minions at neutral camps can be defeated to gain experience points, and become mercenaries that fight for the player\'s team. Each map has a different side-objective that will help either team and deal significant damage to the other.