Yin and Yang are also used by structures in the faction's base for military upgrades. Hero units, or Zen Masters, require Yin/Yang to be summoned and increase their damage. Each army obtains points of Yin or Yang when in combat, depending on their moral alliance to the forces of light or darkness. BGs also allow the player to further define the role of a unit, such as damage absorption, building destruction, or reconnaissance.Another key element of Battle Realms is the Yin/Yang system. This allows lower tiered units to defeat higher tier units, which they could not normally defeat. In most cases, units can be trained in three different structures to produce more highly skilled infantry or Battle Gears (commonly abbreviated as BGs) to improve their combat ability. Most of the buildings available are training structures where peasants are trained to become other units.All factions start off with three basic training structures which produce units along different paths of warfare, such as melee or ranged combat. Peasants are the only units that can be produced outright. Only one type of builder unit is required. They also round up horses which can be used to enhance military units or can be outfitted as pack horses for peasants. The rate at which new peasants are produced is inversely proportionate to the current population of the player's army.Peasants gather two resources in the game: rice and water. Thus, military buildings in Battle Realms are used for transforming and upgrading units rather than producing them directly.Another unusual trait is unit generation, where peasants are produced automatically at no cost. Unlike other real-time strategy games though, the basic worker units (peasants), which are used for resource gathering and construction, also act as the base unit to be upgraded into military units.

There are several factions which all have various types of available structures and units to produce. Battle Realms' gameplay is like many other real-time strategy games.

Game battle realms 1