Mecha

Mecha is a catch-all term for a large variety of vehicles characterized by possessing limbs for locomotion or manipulation. Many mecha bear at least a slight resemblance to the human form. They are sometimes also referred to as mechs or giant robots, though the latter term is not exactly correct as a true mecha requires a pilot to function under most circumstances, while a robot is entirely autonomous.

In the Grand Combat
Many warriors chosen for the Grand Combat do not fight on foot, but rather by using a combat vehicle. For many pilots, a mecha is their vehicle of choice. Mecha have been excluded from rounds  in the past as their large size would put them in an unfair advantage in many situations. At other times, combatants in mecha fight alongside and against those on foot.