Battle Realms is a real-time strategy video game published and released by Crave Entertainment and Ubi Soft in November 2001. It was the first game created by Liquid Entertainment. An expansion pack Battle Realms: Winter of the Wolf was released in November 2002. In 2012, the game was re-released on GOG.com. In 2019, the game was re-released on Steam as Battle Realms: Zen Edition, in its early access state with functioning online multiplayer. Gameplay Battle Realms''' gameplay is like many other real-time strategy games. There are several factions which all have various types of available structures and units to produce. 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. 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. The rate at which new peasants are produced is inversely proportionate to the current population of the player's army. Peasants gather three resources in the game: rice, water and horses. Horses are war units that can be used to combine with other military units i.e. riding or can be turned into pack horses when assigned for peasants. Only one type of builder unit is required. Peasants are the only units that can be produced outright. 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. 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. This allows lower tiered units to defeat higher tier units, which they could not normally defeat. 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. Each army obtains points of Yin or Yang when in combat, depending on their moral alliance to the forces of light or darkness. Hero units, or Zen Masters, require Yin/Yang to be summoned and increase their damage. Yin and Yang are also used by structures in the