The Challenger 2 Black Night MBT (Main Battle Tank) uses the same turret as the standard Challenger 2 that is mounted in the center of the hull. Main armament includes consists of one BAE Systems L30A1 RO Defence 120 mm rifled tank gun fitted with a thermal sleeve, fume extractor and muzzle reference system. It can fire all the standard 120mm ammunition, up to 50 projectiles can be carried inside of the tank. Second armament includes one coaxial ATK Gun Systems Company 7.62 mm Chain Gun called L94A1 in the British army mounted to the left of the main armament. One 7.62mm L37A2 machine gun is mounted on the loader hatch. A bank of five 66mm electrically operated smoke grenade dischargers is mounted on either side at the front of the turret. The turret is fully electrically operated by commander and gunner with 360° turret traverse and gun elevation of +20° and depression of -10°.

The layout of the Challenger 2 Black Night MBT is similar to the original Challenger 2 except for the turret which is equipped with additional systems including night vision equipment, active protection and laser warning systems. The tank has a crew of four including driver, commander, loader and gunner. The driver position is located at the center of the hull. In the turret, the commander is seated on the right, the gunner forward and below the commander, and the loader on the left side. The Challenger 2 is built from conventional steel armor covering both the hull and turret providing high level of protection against ballistic threats and artillery shell splinters. The turret also incorporates second-generation of Chobham armor to increase protection against both KE (Kinetic-Energy) and CE (Chemical-Energy) rounds attacks and incorporates stealth technology to minimize the radar signature. The frontal armor was designed to resist all KE threats at point blank except the Soviet 115 mm APFSDS - this could penetrated the front at 200 meters according to British estimates. The side armor could stop 76 mm AP-T at 2,000 meters and 50° angle, 57 mm AP-T at 2,800 m and 50° angle and 45 mm AP-T at 1,000 m and 40° angle. It also provided full protection against Carl Gustav ammunition, 6 inch and 5 inch shaped charge warheads at angles greater than 65° and 60° respectively. This protection assessment is based on British calculations made with penetration figures for Soviet weapons provided by the US Army. For its self-protection, the Black Night Challenger 2 is fitted with a new Iron Fist APS (Active Protection System) from IMI (Israel Military Industries) mounted on each sides at the front and the rear of the turret. The roof of the turret is also equipped with two banks of launchers parts of Iron Fist APS, able to fire countermeasure munitions to defeat and/or deflect anti-tank guided missiles and rocket-propelled grenades away from the tank. It senses incoming threats via a fixed active electronically scanned array radar sensor developed by RADA Electronic Industries and an optional passive infrared detector developed by Elbit's Elisra. When a threat is imminent, an explosive projectile interceptor is launched towards it. The interceptor explodes very near the threat, destroying or deflecting and destabilizing it without detonating its warhead. For this, only the blast effect of the explosive is used. The interceptor casing is made of combustible materials so no fragmentation is formed in the explosion, helping minimize collateral damage.