Because the gameplay revolves around strengthening individual heroes, it does not require focus on resource management and base-building, unlike most traditional real-time strategy games. Killing computer-controlled or neutral units earns the player experience points; the player gains a level when enough experience is accumulated. Leveling up improves the hero's toughness and the damage they inflict, and allows players to upgrade spells or skills. In addition to accumulating experience, players also manage a single resource of gold. The typical resource-gathering of Warcraft III is replaced by a combat-oriented money system; in addition to a small periodic income, heroes earn gold by killing or destroying hostile units, base structures, and enemy heroes. This has caused emphasis on a technique called "last-hitting," which is when the player attacks a hostile unit when "its hit points are low enough to kill it with one blow". Using gold, players buy items to strengthen their hero and gain abilities; certain items can be combined with recipes to create more powerful items. Buying items that suit one's hero is an important tactical element of the mod.