IIC ("two-C", in the sense of "second generation, and of Clan origin") is an Inner Sphere designation[1] for items of superior Clan technology that have evolved out of certain classic designs or items from which they derive their names. It was coined for certain BattleMech designs,[1] but was later also used for superior (Clan-level) technology rebuilds of aerospace fighters, vehicles, and other equipment that had recognizably evolved out of an earlier namesake, and is now used for a broad range of advanced items.

They are invariably considered distinct designs, and not as subvariants of their namesake precursor designs. Many IIC designs have altered the parent design's mass and some bear only a superficial semblance to the earlier design or item of the same name.

The IIC designation originated with the Inner Sphere,[1] and is not a Clan term, describing Clan technology from an Inner Sphere viewpoint. As such, the Clans themselves did not use the IIC description initially, referring to IIC units and items by their traditional Star League-era name (without the "IIC" appendix) instead.[2] Later on, around the Jihad era past the year 3067, the Clans seem to have adopted IIC as a designation[3] to differentiate the newer IIC designs from their old-fashioned ancestors of the same name which are sometimes still in use in the Inner Sphere. Note that the Clans have abandoned the alphanumerical designator system for 'Mechs and aerospace fighters that has been in use in the Inner Sphere since the days of the Star League. Thus, they would refer to a Locust IIC as either a Locust or a Locust IIC, but never as a LCT-IIC.

Among the BattleTech fanbase, "IIC" is also (usually jokingly) used very broadly for the concepts of superiority or improvement; it is unclear if the designation is in similarly casual use within the BattleTech universe.[citation needed]

Although superior to standard Inner Sphere technology, IIC 'Mechs and fighters do not make use of Omni technology and were thus already considered obsolete by Clan standards around the time of the Clan Invasion. With the notable exception of the Hunchback IIC,[4][5] IIC BattleMechs were largely absent from frontline formations, and were initially primarily used in second-line and garrison units.[1] Still, the concept carries on, and new IIC designs were still devised by 3095.[6]

No IIC Spaceships[edit]

Even though similar redesigns exist among spacecraft, spaceships of all kinds seem to be a notable exception from the IIC naming scheme if they are larger than an aerospace fighter (there is at least one IIC aerospace fighter design):

  • Small Craft exist in upgraded versions among the Clans, but instead of IIC these simply append "C" to their designation either directly, or separated by a space or a dash, e.g. K-1C, KR-61 C, Mark VII-C.[7] It should be noted though that Clan upgrades to Small Craft designs are typically minor, usually limited to an upgrade of their weapons suite to more advanced versions of the same weapons, and/or armor changes. In this fashion, they are actually much closer to "C" variants (see below) than IIC redesigns, although unlike "C" BattleMechs which are stopgap upgrades of obsolete designs, these upgraded small craft seem to be the Clans' baseline production models.
  • DropShips are either treated like small craft, or received entirely new names: Despite effectively being IIC-style redesigns, the Union-C and Overlord-C are named thus, even by the Clans themselves, while the IIC-style evolution of the Leopard and Intruder were named the Broadsword and Sassanid-class, respectively. Despite the differences, initial Inner Sphere reports during the early Clan Invasion often inaccurately reported Union-C and Overlord-C-class DropShips as Union and Overlord-class vessels, and Broadsword-class DropShips as Leopards.[8]
  • JumpShips: The Clans do operate upgraded versions of common JumpShip types with (it is implied) improved onboard electronics and other advanced technologies such as HarJel hull sealant safety systems, but the overall differences seem to be minor and they are not named differently.
  • WarShips: There is no IIC WarShip class, despite many vessels in the Clan fleets having undergone some form of upgrade or refit—sometimes radically so, as there are entire new ship classes that were created by revamping and upgrading an existing class. Such evolutions that were based off older designs were given entirely new names, however.

Difference between "IIC" and "C" designs[edit]

IIC BattleMechs are by definition new 'Mech models designed from a namesake parent design to make use of Clan technology. They should not be confused with "C"-style variants or refits of BattleMechs which are typically identified by appending "(C)" to their alphanumerical designation:

Somewhat similar to the IIC concept, "C"-type BattleMechs are standard 'Mech designs that feature advanced Clan equipment and components, but are essentially only a variant of their parent design built with better components and not an altogether new design (as opposed to a IIC 'Mech that has been redesigned from the ground up). Frequently, the change is limited to exchanging weapon systems for advanced Clan counterparts, without changing the chassis or other components such as the fusion engine or heat sinks.

These upgraded variants are typically built by the Clans at captured Inner Sphere factories as a stopgap measure to achieve the best possible production result without having to retool the factory for an entirely different 'Mech model.

Known IIC designs[edit]

Note: This list may be incomplete.


Aerospace fighters[edit]



  • Mauser IIC assault rifle
  • Kobold IIC battle armor; a Clan upgrade version of an Inner Sphere battle armor design that was created after the Inner Sphere had reverse engineered battle armor technology from the Clans


  1. 1.0 1.1 1.2 1.3 Technical Readout: 3055, p. 92: "Clan BattleMechs"
  2. Trial of Faith, p. 13 provides one example where what Clan forces describe as "Locust" 'Mechs are clearly Locust IIC.
  3. Operation ICE STORM Part 2, p. 7
  4. 4.0 4.1 Technical Readout: 3058, p. 188
  5. 5.0 5.1 Technical Readout: 3058 Upgrade, p. 172
  6. The Viking IIC was introduced in 3095
  7. Technical Readout: 3057 Revised, pp. 170–171, 173
  8. There is an official ruling to the effect that Clan DropShips described as Overlord and Union in early sourcebooks, especially those sourcebooks that predate the introduction of proper Clan DropShips in Technical Readout: 3057, can be considered to be Overlord-C and Union-C-class vessels instead; the same is "not definitely" true for Broadsword/Leopard-class vessels. It should be noted though that one sourcebook written as an internal Wolfnet document (The Falcon and the Wolf) lists Overlords, Unions, Leopards and Intruders in Clan toumans alongside Overlord-C, Union-C, Broadsword and Sassanid-class vessels; given that Wolfnet would be aware of the differences this seems to prove that all of those classes were in fact in use among the Clans at least up until ca. 3057, when the report was compiled in-universe