Warcraft III: Reign of Chaos is a high fantasy real-time strategy video game released by Blizzard Entertainment on July 3, 2002 in the U.S. It is the second sequel to Warcraft: Orcs & Humans, and it is the third game set in the Warcraft fictional Universe. An expansion pack, The Frozen Throne, was released on July 1, 2003.

Warcraft III contains four playable races:Humans and Orcs, which had previously appeared in Warcraft: Orcs & Humans andWarcraft II: Tides of Darkness, and the Night Elves and Undead, which were introduced to the Warcraft mythos in this installment.Warcraft III‍ '​s single-player campaign is laid out similarly to that of StarCraft, also by Blizzard Entertainment, being told through all four of the game's races in a progressive manner. Multiplayer mode allows for play against other players, via the internet, instead of playing against computer-controlled characters as is done in the single-player custom game mode.

Gameplay:

Warcraft III takes place on a map of varying size, such as large plains and fields, with terrain features like rivers, mountains, seas, or cliffs. In Campaign mode, the map is initially covered with the Black Mask, an impenetrable covering. The Mask is removed from areas that have been explored, but those that are no longer within sight range of an allied unit or building are instead covered with thefog of war; though terrain remains visible, changes such as enemy troop movements and building construction are unseen. During a game, players must establish settlements to gain resources, defend against other players, and train units to explore the map and attack computer controlled foes. There are three main resources that are managed inWarcraft III: gold, lumber, and food. The first two are required to construct units and buildings, while food restricts the maximum number of units the player may control at one time.

(From Wikipedia)