A pitched battle or set-piece battle is a battle in which opposing forces each anticipate the setting of the battle, and each chooses to commit to it. Either side may have the option to disengage before the battle starts or shortly thereafter. A pitched battle is not a chance encounter such as a meeting engagement, or where one side is forced to fight at a time not of its choosing such as happens in a siege or an ambush. Pitched battles are usually carefully planned to maximize one's strengths against an opponent's weaknesses and use a full range of deceptions, feints, and other manoeuvres. They are also planned to take advantage of terrain favourable to one's force. Forces strong in cavalry, for example, will not select swamp, forest, or mountain terrain for the planned struggle. For example, Carthaginian General Hannibal selected relatively flat ground near the village of Cannae for his great confrontation with the Romans, not the rocky terrain of the high Apennines. Likewise, Zulu Commander Shaka avoided forested areas or swamps, in favour of rolling grassland (flat or on mountain slopes), where the encircling horns of the Zulu Impi could manoeuvre to effect. A pitched battle can decide the outcome of a war or military operation. Pitched battles continued to evolve throughout history as armies implemented new technology and tactics.
During the Prehistorical period, pitched battles were established as the primary method for organised conflict and placed an emphasis on the implementation of rudimentary hand and missile weapons in loose formations. This developed into the Classical period as weapons and armour became more sophisticated and increased the efficacy of heavy infantry. Pitched battles decreased in size and frequency during the Middle Ages and saw the implementation of heavy cavalry and new counter cavalry formations. The early modern period saw the introduction of rudimentary firearms and artillery developing new tactics to respond to the rapidly changing state of gunpowder warfare. The late modern period saw improvements to firearms technology which saw the standardisation of rifle infantry, cavalry and artillery during battles. Pitched battles declined towards the late 19th century and had ceased by the First World War because of technological developments establishing trench warfare. Whilst there are a few examples of pitched battles that occurred on a large scale during the Second World War, during the Post-war period, pitched battles effectively ceased to exist because of the prevalence of irregular warfare. The largest set-piece battle in the history of warfare was the Battle of Kursk.