the M6A1 Raider Main Battle Tank was the primary heavy armoured vehicle used by the United Nations Space Command following the Human-Covenant War. Replacing the venerable M808B Scorpion MBT in the main battle tank role, the Raider was up-armoured and up-gunned from its predecessor, while being faster, lighter and more capable against soft targets. Incrementally replacing the Scorpion from 2558 over a period of seven years, the Raider's flexibility made it widely used by the UNSC Marine Corps, who benefited from its superior speed and agility without compromise of armament or protection. Seeing widespread usage against Covenant forces, the Raider surpassed even the Scorpion's effectiveness in battle against enemy infantry and armour.