[15][16] The tank is named after Arjuna, the archer prince who is the main protagonist of the Indian epic poem Mahabharata.

[24] From 1993 to 1996, the Indian Army carried out an extensive series of trials, which revealed some major defects in the tank, including the engine overheating and suboptimal performance of the weapons system.

[N 2] By the end of 1996, 14 pre-production series (PPS) tanks (PPS-1 to PPS-14) were built and delivered to the Indian Army to conduct trials.

[27][28] The initial delays and cost escalations were attributed to the sequential revisions done to the original General Staff Qualitative Requirement (GSQR) issued in 1974 to accommodate new features.

[1] By 1999, both the Army and Cabinet Committee on Security (CCS) gave clearance for a limited production run of the Arjun main battle tank based on the PPS-15 prototype.

[N 3][1] One Arjun tank (PPS-15) operated by the 43rd Armoured Regiment made a public appearance in the 1997 and 2001 Republic Day Parades.

[34][35] In 2009, an advanced laser warning countermeasure system (ALWCS) and a fibre-optic gyro-based sensor package unit was developed and integrated on the Arjun MK1 main battle tank after field trials were carried out in two phases from May to August 2009.

In the same year, the Indian Army placed an order for the procurement of 124 Arjun MK2 tanks, which was later approved by the Defence Acquisition Council (DAC).

[45] The Arjun main battle tank has a 120 mm rifled gun fitted with an ARDE-developed (Armament Research and Development Establishment) recoil system, muzzle reference system and fume extractor, which can fire a variety of guided or unguided anti-armour munitions.

[46] The main gun is made from high strength electro-slag remelting (ESR) steel which is insulated with a thermal sleeve and autofrettaged to withstand higher pressure.

[22][47][48] The Arjun MK1 can fire several types of munitions, including indigenously developed armour-piercing fin-stabilized discarding sabot (APFSDS) and dual purpose high-explosive squash head (HESH) rounds.

[52][53] To enhance the firepower of the Arjun, DRDO earlier considered equipping the tank with a LAHAT gun-launched anti-tank guided missile, but in 2014, it was announced the plan had been dropped.

[55] The SAMHO guided missile has two high-explosive anti-tank (HEAT) tandem-charge warheads designed to defeat explosive reactive armour (ERA) protection.

[31] The IFCS consists of a digital ballistic computer which cues information from microprocessor-based sensors for wind-speed, tilt angle, target range, vehicle speed etc., to provide an accurate firing solution.

[19] The Arjun's IFCS is designed for quick target acquisition with "first round-first hit probability" during day and night and in all weather conditions.

[37] The sight is also interfaced with the ballistic computer, which enables the commander to override the gunner to select and engage targets independently.

[61] The armour was fielded on the Arjun after extensive evaluation trials carried out against a variety of modern anti-tank munitions, including APFSDS.

[63][64] The latest variant Arjun, the Mk1A, has a completely redesigned turret protected with improved Kanchan armour with enhanced protection against large calibre kinetic energy projectiles,[40] explosive reactive armour (ERA) panels (ERA MK-II) on the turret, hull glacis and the side skirt.

[65] Passive protection is provided by a multi-purpose mobile camouflage system (MCS) developed by DRDO; it is integrated on Arjun tanks and evaluations were carried out in 2009.

[67] The ALWCS has integrated IR jammers and aerosol based smoke grenades to confuse the anti-tank guided munitions.

[58] In Arjun Mk1A, the driver's safety and comfort is enhanced with roof mounted seat to protect him from Shock waves.

[58] The Arjun is a heavy main battle tank that moves on seven roadwheels on each side, supported by an indigenously developed hydropneumatic suspension system.

[58] As reported in 2010, an indigenous engine, capable of providing a power output of 1,500 hp (1,100 kW) was to be developed for DRDO's Future Main Battle Tank (FMBT) programme.

The indigenous engine along with the transmission will be collectively form the Bharat Power Pack which will meet the FMBT's mobility requirements.

The IAVS monitors the data bus that interlaces the hull and turret subsystems, analyses automotive performance and alerts the crew when maintenance is due.

[43] Its trials were successfully completed in August 2015 during which the prototype covered 430 kilometres (270 mi) under harsh weather conditions.

In addition, it demonstrated a zero water ingress medium fording capability, multiple target discrimination, and effortless automotive performance achieved even in the heavy dunal desert terrain.

[21] In 2014, a report from the Comptroller and Auditor General of India noted that some parameters of the 2010 comparative trials had been relaxed for the T-90 tanks.