Production information
Manufacturer Defiance Industries[1]

Hellespont 'Mech Works

Maltex Corporation (-21; destroyed 2835)[2]

Production Year 2676[3]
Model ASN-21[2]
Class Medium
Cost 3,765,813 C-bills
Technical specifications
'Mech type Inner Sphere BattleMech
Mass 40 tons
Chassis Maltex 40
Armor 100 AFVTA
Engine VOX 280
Communications System Garret T15 B
Targeting Tracking System Garret 500S
Heat Sinks 10 single
Speed 118 km/h
Jump Jets Lox Lift Series 1
BV (1.0) 596[4]
BV (2.0) 749[2][5]


The Assassin is a BattleMech that began life because of corporate ambitions and successful lobbyists. Though there was no need for a new medium 'Mech in its arsenal, the Maltex Corporation lobbied the Star League to purchase the Assassin as a replacement for the lighter Wasp and Stinger. They were successful largely through over-hyped performance statistics, fuzzy budget approximations, and some greased palms, and even then only several hundred were constructed before production slowed to a crawl after two Assassin factories came under investigation for quality control violations. Still, the Assassin proved to be popular with garrison forces of the SLDF and the Marik Militia; with an impressive top speed and jumping distance of 210 meters combined with excellent coverage for its four and a half tons of armor and solid firepower, the Assassin was considered a superb reconnaissance and light 'Mech hunter in its own right.[6][7][8]

The Assassin was not flawless however, especially when Maltex cut corners during its initial production, and it has the dubious distinction of having one of the most cramped cockpits of any Inner Sphere 'Mech. Dozens of attempts by Maltex over hundreds of years to overhaul the cockpit cooling system to create more elbow-room ended in failure, not only limiting Assassin pilots' time in-cockpit to half of that of other 'Mechs, but causing many to develop a lifetime of back problems. The Assassin would first see combat in 2980, long after the fall of the Star League, when the Free Worlds League successfully fought off the Federated Suns for control of Rochelle during the Third Succession War. The Assassin fared better than other 'Mechs during the bloody battle and House Marik became an enthusiastic user of the design late into the war. Eventually the use of Assassins by all sides lessened due to a shortage of spare parts, with the Capellan Confederation simply running out of these 'Mechs by 3025, though its modular design and access systems allowed it to survive.[7][8]

By 3058, most Assassins had been phased out of service, with the remaining 'Mechs mostly family heirlooms passed down through MechWarrior families and with many modifications. Defiance Industries was licensed by Maltex to produce a variant, the ASN-30, for the Lyrans during the FedCom Civil War, but it was largely seen as a failure. The Assassin would see a resurgence in 3067 when Hellespont 'Mech Works acquired the design from Maltex, thanks in part to minor distractions facing Maltex such as charges of tax evasion and collusion with the Word of Blake, and began producing the ASN-23 for the Capellans, the Taurian Concordat, and the Magistracy of Canopus.[9]

Weapons and Equipment[edit]

The Assassin is popular for its long-range capabilities thanks to a Holly-5 LRM-5 launcher in the right side of its torso. Its primary short-range weapon is a Holly-2 SRM-2 launcher in the torso's left side, supported by a Martell medium laser in the right arm. With just two tons of missile ammunition, one ton of LRM and one ton of SRM ammunition, the 'Mech has limited endurance on extended operations without resupply and is vulnerable when left with only the laser to fight back. Assassins built before 2815 also suffered from a serious design flaw in the short-range missile rack's reloading mechanism, which experienced chronic jamming during high-heat situations and could only be repaired by disassembling the unit. Under severe corporate pressure Maltex finally fixed the problem in newer models and offered several years' funding for recall repairs, though some privately-owned Assassins might still mount the defective system.[7][8]


  • ASN-23 
    The -23 variant of the Assassin is an upgrade of the original model using lostech; originally seen as a standardized field modification,[10] in 3067 new production began at Hellespont 'Mech Works. The SRM-2 has been removed to upgrade the medium laser to a medium pulse laser, typically the "readily available" Magna 400P,[10] and an Artemis IV fire control system has been added for the LRM-5 launcher. Within the CCAF, TDF, and MAF it is largely used as a cheap way to rebuild shattered forces and sees service mostly in green and reserve formations. The Capellans in particular use the -23 as a fire-support unit for pursuit and strike lances, though shortages of Artemis munitions means many are forced to use mine-delivery missiles.[9] BV (1.0) = 609[4], BV (2.0) = 740[11]
  • ASN-30 
    The -30 variant of the Assassin, produced under license by Defiance Industries, was a radical departure from the classic formula for the 'Mech. The chassis was redesigned to utilize endo steel construction and the engine upgraded to a light fusion engine. The saved weight was used to upgrade the medium laser to an ER medium laser, and the LRM-5 and SRM-2 are removed in favor of an LB-X AC/5. Additionally, the armor had been increased by two full tons and the single heat sinks upgraded to double strength versions. Used by the Lyran side of the FedCom Civil War, this design is considered a failure and few of them were ever produced.[9] BV (1.0) = 846[12], BV (2.0) = 925[13]
  • ASN-99 
    When Hellespont 'Mech Works first acquired the Assassin from the Maltex Corporation, the ASN-99 was the original testbed design. Incorporating more armor than any previous variant, thanks in large part to the inclusion of an XL engine, its long-range punch is provided by a light PPC, while it can rely upon two SRM-2s at close range. Target Acquisition Gear enables it to call down supporting fire should the Assassin find itself embroiled in a fight. This variant also mounts stealth armor and a sword. BV (1.0) = ??, BV (2.0) = 1,116[14]
  • ASN-101 
    The -101 Assassin was an unofficial variant produced in limited numbers by the Federated Suns during the Succession Wars. Removing some of the 'Mech's seven jump jets and shaving off a half ton of armor, they were able to fit three Maxell 50 small lasers, one in each leg and the third in the head. The design was seen as a failure, especially since it sacrifices 60 meters of the 'Mech's immense jumping distance, and only three were purported to have been built and stationed with the Capellan March Militia, though some cite circumstantial evidence of more constructed in secret.[2][7][8] BV (1.0) = 586, BV (2.0) = 757[15]
  • ASN-109
    This new CCAF version of the Assassin shares a large number of parts with the Raven II to improve logistics and replacement. A capable machine, it is protected with Stealth Armor and an Angel ECM Suite, protecting a 280-rated XL engine and a Small Cockpit. The space saved by this is spent on weaponry, with a Light PPC being mounted in the right arm cannon module, while an MML 5 with 2 tons of CASE II-protected ammunition is mounted in the right torso. An Improved One Shot SRM 2 is generally loaded with specialty warheads as well. BV (1.0) = ???? BV (2.0) = 1,158[16]

Custom Variants[edit]

Apocryphal Variants[edit]

Apocryphal Content Starts

The information after this notice comes from apocryphal sources; the canonicity of such information is uncertain.
Please view the reference page for information regarding their canonicity.

From BattleTechnology Issue 202:

  • ASN-SB 
    Reportedly developed by the crack techs of the Hat-in-the-Ring Battalion mercenary unit and becoming a routine modification within the unit, the ASN-SB drops the SRM-2 rack and its ammunition in exchange for another medium laser and some additional armor.[19]

From MechWarrior 5: Call to Arms Expansion Pack:

  • ASN-25 
    Introduced in 3026 to tap into the rise of interest in melee weapons, the ASN-25 retains the right arm's medium laser, but replaces the remaining weaponry with a right torso-mounted medium laser and left torso-mounted small laser, the weight saved to mount a medium claw in the left arm.[20]

From MechWarrior Online:

  • ASN-26 
    A 3050's tech version of the -30, the -26 also uses an endo steel chassis but mounts an XL engine, the extra weight saved allowing the 'Mech to carry an UAC/5 and a pair of medium pulse lasers for offensive armament. Field endurance is limited however, as six and half tons of armor provided basic protection, and a single ton of autocannon reloads are chewed through rapidly. The 10 double heat sinks struggle to manage heat strain.[21]
The MechWarrior 5: Heroes of the Inner Sphere DLC version of MWO's ASN-27 retains the TAG.[22]

Apocryphal Content Ends

Design Quirks[edit]

The Assassin has the following Design Quirks:[23]

Notable pilots[edit]

See: Category:Notable Assassin Pilots


  • Author Blaine Lee Pardoe stated in a blog entry that, according to his memory which he admitted could be wrong, the Assassin was among the BattleMechs for which he wrote the original background as initially published in TRO:3025, after being given only its name, image, and game stats to work with for the TRO entry.
  • In German products, the unit's proper name was translated to Attentäter. The model code was accordingly changed to ATN-21.
  • In French products, the unit's proper name was kept as Assassin, which has the same meaning in both languages.



  1. Objectives: Lyran Alliance, p.12
  2. 2.0 2.1 2.2 2.3 Technical Readout: Succession Wars, pp. 52–53: "ASN-21 Assassin"
  3. MUL online entry for Assassin
  4. 4.0 4.1 Combat Operations, p. 121
  5. Record Sheets: 3039, p. 94
  6. Classic BattleTech Introductory Record Sheets, pp 6
  7. 7.0 7.1 7.2 7.3 Technical Readout: 3025, p. 34-35, "Assassin Profile"
  8. 8.0 8.1 8.2 8.3 Technical Readout: 3039, p. 116-117, "ASN-21 Assassin"
  9. 9.0 9.1 9.2 Technical Readout: 3050 Upgrade, p.34-35, "Assassin Profile"
  10. 10.0 10.1 Technical Readout: 3050, Revised, p.82
  11. Record Sheets: 3050 Upgrade (Inner Sphere), p. 72
  12. Record Sheets: Upgrades, p. 58
  13. Record Sheets: 3050 Upgrade (Inner Sphere), p. 73
  14. Record Sheets: 3050 Upgrade, Inner Sphere p. 74
  15. Record Sheets: 3039, p. 93
  16. Recognition Guide: ilClan, vol. 29, p.12
  17. Record Sheets: Unique 'Mechs, p. 2, "Assassin Alice"
  18. Record Sheets: 3050 Unabridged (Inner Sphere), p.75
  19. BattleTechnology Issue #0203, p. 34
  20. MechWarrior 5: Mercenaries, Call to Arms
  21. 21.0 21.1 21.2 MechWarrior Online - Assassin Sale Page
  22. MechWarrior 5: Mercenaries, Heroes of the Inner Sphere
  23. BattleMech Manual, p. 90 BattleMech Quirk Table - Assassin Entry.