Diablo II, sequel to the popular game Diablo, is a dark fantasy-themed Action role-playing game in a hack and slash or "dungeon roaming" style. It was released for both Microsoft Windows and Mac OS in 2000 by Blizzard Entertainment. Diablo II was developed by Blizzard North.
The game continues the storyline from the first game. The player follows in the path of Diablo who heads eastward from Tristram to free his two imprioned brothers Mephisto and Baal. Unlike the first game which took place underground, Diablo II features many outdoor regions ranging from desert to jungle} and eventually hell itself. Other notable changes are the five new characters each with 30 unique skills, a larger array of monsters and items, a greater ability to build characters and a more fleshed out story and world.
By April 2001, Diablo II had become one of the most popular online games ever. Major factors that contributed to Diablo II's success include what fans found to be addictive hack and slash gameplay and free access to Battle.net. Diablo II may be played as a single player game, multiplayer via a LAN over TCP/IP, or multiplayer via Battle.net, with the latter being the most popular. It has also become one of the top thirty best selling computer games ever. Including Diablo II, the Diablo series has sold 17 million copies.
An expansion to Diablo II, Diablo II: Lord of Destruction, was released in 2001. The expansion finished the story arc begun in Diablo II as the player kill Baal, the last surviving Prime Evil. The gameplay remained largely the same as the core game and mostly expanded the content with a brand new act, two new classes, a new rune word mechanic, new monsters and items as well as various minor additions and fixes.