Why were Mongol military tactics most effective on open plains?

Mongol military tactics were most effective on open plains because their armies were primarily composed of highly mobile cavalry. This reliance on horse-mounted warriors allowed them to utilize speed and complex maneuvers to disorganize enemy ranks before engaging in close-quarters combat.1

The open terrain of the Eurasian Steppe was ideally suited for these forces, as it provided the necessary space for their horses to operate efficiently. In contrast, mountainous or wooded regions hindered the mobility that was central to their strategy and tactics. By operating on flat ground, Mongol forces could easily probe for weaknesses in enemy defenses and swiftly exploit any gaps they discovered. Their reliance on the composite recurved bow also favored open environments, where their ability to harass enemies from a distance while remaining mounted provided a significant tactical advantage.123