List of Blizzard Entertainment games
Since the release of "Warcraft", "Diablo", and "StarCraft" (1998), Blizzard has focused almost exclusively on the "Warcraft", "Diablo", and "StarCraft" series. The sole exception has been the company's latest title, "Overwatch" (2016). All of Blizzard's games released since 2004 still receive expansions and updates, especially the long-running massively multiplayer online role-playing game "World of Warcraft" (2004). With over 100 million lifetime accounts as of 2014 and US$9 billion in revenue as of 2017, "World of Warcraft" is one of the best-selling computer games and highest-grossing video games of all time. Blizzard Entertainment has developed 19 games since 1991 as of 2018, in addition to developing 8 ports between 1992 and 1993; 11 of those games are in the "Warcraft", "Diablo", and "StarCraft" series.
Hearthstone
Of the game types they explored, Team 5 soon focused on the collectible card game approach, given that many on the team and in Blizzard had played such games since their introduction. The team found it natural to build the card game around the existing "Warcraft" lore; according to production director Jason Chayes, "Warcraft" was already a well-known property, and the depth of characters and locations created for other games in that series made it easy to create cards inspired by those. They also saw that new players to "Warcraft" may be drawn into the other games through playing "Hearthstone". The team was able to pull concepts and art from the pre-existing "World of Warcraft Trading Card Game", first published in 2006 by Upper Deck and later by Cryptozoic Entertainment; when "Hearthstone" was near completion, in 2013, Blizzard terminated its license with Cryptozoic as to favor their pending digital card game. The addition of heroes, an aspect from the previous trading card game, was found to help personalize the game for the player to allow players to discover useful combinations of cards for each hero.