Alpha

The alpha phase of Heroes of the Storm included both the developmental phase which began from at least 2011 and the "Technical Alpha" phase which began on March 2014. The alpha ended on January 13, 2015, when the game entered its beta phase.

An alpha test is the phase of testing before beta testing. It represents a product which is not yet fully functional, but which is being tested among a relatively select group. Once all major features have been implemented and major bugs fixed, the game will likely move on to the beta testing phase, with release to a far larger group of players.

Technical Alpha
This section provides a brief overview of the game's Technical Alpha.

For a list of patches released over the course of the Technical Alpha, including detailed patch notes, see Patches.

Content
Blizzard released the game's Technical Alpha to a limited selection of the public on March 10th, 2014.

The alpha was released with 23 heroes and 4 battlegrounds. 8 heroes were assassins, 7 were warriors, 4 were supports, and 4 were specialists. 10 heroes were from the Warcraft universe, 8 were from the StarCraft universe, and 5 were from the Diablo universe.

Diablo

 * Sonya, a warrior.
 * Valla, an assassin.
 * Diablo, a warrior.
 * Tyrael, a warrior.
 * Nazeebo, a specialist.

StarCraft

 * Abathur, a specialist.
 * Kerrigan, an assassin.
 * Nova, an assassin.
 * Raynor, an assassin.
 * Sgt. Hammer, a specialist.
 * Tassadar, a support.
 * Tychus, an assassin.
 * Zeratul, an assassin.

Warcraft

 * Arthas, a warrior
 * E.T.C., a warrior.
 * Falstad, an assassin.
 * Gazlowe, a specialist.
 * Illidan, an assassin.
 * Malfurion, a support.
 * Muradin, a warrior.
 * Stitches, a warrior.
 * Tyrande, a support.
 * Uther, a support.

Battlegrounds

 * Blackheart's Bay
 * Cursed Hollow
 * Dragon Shire
 * Haunted Mines
 * Garden of Terror