Additionally, a new 'upkeep' system means that producing units over certain amounts will decrease the amount of gold one can earn, compelling players to focus on playing with a limited number of units to avoid penalties. The map is initially hidden from view and only becomes visible through exploration. Areas no longer in sight range of an allied unit or building are covered with the fog of war, meaning that while the terrain remains visible, changes such as enemy troop movements and building construction are not. During a game, players must establish settlements to gain resources, defend against others, and train units to explore the map and fight computer controlled foes. There are three main resources that are managed in Warcraft III: gold, lumber, and food. The first two are required to construct units and buildings, while food restricts the maximum number of units that can be possessed at the same time.
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.