Traditionally, a mobile weapon uses one of two variants of this system:
- A mobile weapon can be created through a series of weapon modules, which includes a Core module for the pilot (typically in the form of a stand-alone fighter plane). While the pilot operates the Core module, they can coordinate the modules into combining into the desired mobile weapon, with the Core module at its base.
- A mobile weapon can be created by having a detachable Core module that houses the pilot, and the entire mobile weapon frame that can only activate when the Core module is attached. The pilot operates the Core module to dock, or "plug-in", to the mobile weapon frame, activating the mobile weapon.
Once the mobile weapon is active, the pilot operates the entire mobile weapon through the Core module, and can also detach or recombine any module(s) from the mobile weapon as needed.
In the Universal Century timeline, the Core Block System was first developed by the Earth Federation in their top secret Project V in the form of the FF-X7 Core Fighter. This feature allow the usage data of a mobile suit to survive even if the mobile suit itself was destroyed. The mobile suit (usually the RX-78-2 Gundam) could be separated and recombined in mid-air, but required the use of additional equipment such as the Gunperry or G-Fighter to transport and prepare the individual components for combination.
The Core Block System was later used in the Gundam Development Project's RX-78GP01 Gundam "Zephyranthes", its Full Burnern upgrade, and subsequently in some Zeta Project's mobile suits such as the MSZ-010 ΖΖ Gundam. The ZZ Gundam's Core Block System allowed its individual components to reconfigure into fighter crafts capable of functioning independently from one another. In addition, the Primrose emergency pod from Advance of Zeta: The Flag of Titans has a similar concept to the Core Block System, but is unable to combine with the mobile suit after separation.
Often times, a mobile suit design constructed with the Core Block System will be refined and simplified into a Mass-Production machine, such as the RGM-79 GM. These Mass-Produced models typically remove the expensive and complicated Core Block System at the beginning stages of development, replacing them with standard construction cockpits.
The Core Block System in the Universal Century would see a brief resurgence during the UC 0130s when SNRI developed the Crossbone Gundam series which used a "plug-in" type Core Fighter.
Afterwards, the Core Block System was not used until the Zanscare War. Although it was mostly featured in the League Militare's LM312V04 Victory Gundam, it nonetheless proved that the concept can be economically effective and even allowed the LM to produce the individual components separately. It also enabled the Victory Gundam and the Victory 2 Gundam to replace damaged parts during combat, by separating then recombining with the new module part.
List of Equipped Mobile Weapons
- RX-75-4 Guntank (FF-X7 Core Fighter)
- RX-77-2 Guncannon (FF-X7 Core Fighter)
- RX-78-1 Prototype Gundam (FF-X5 Prototype Core Fighter)
- RX-78-2 Gundam (FF-X7 Core Fighter)
- RX-78-3 "G-3" Gundam (FF-X7 Core Fighter)
- FA-78-1 Full Armor Gundam (FF-X7 Core Fighter)
- RX-78GP01 Gundam "Zephyranthes" (FF-XII Core Fighter II)
- MSZ-010A1 Theta Plus
- RX-9 Narrative Gundam
- RX-99 Neo Gundam
- F90III-Y Cluster Gundam
- MSZ-010 ΖΖ Gundam (FXA-07GB Neo Core Fighter)
- MSA-0011 S Gundam (FXA-08GB G-Core)
- ORX-008 Gundam ［Gullinbursti］
- X-0 Crossbone Gundam Ghost
- XM-X1 Crossbone Gundam X-1
- XM-X2 Crossbone Gundam X-2
- XM-X3 Crossbone Gundam X-3
- XM-10 Flint
- LM312V04 Victory Gundam
- LM314V21 Victory 2 Gundam
Simplified versions of the Core Block System called Core Landers are used in Mobile Fighter G Gundam, these Core Landers can function as "hovercrafts" and contain the backpack for the Mobile Fighter. (Please see List of Future Century Mobile Units for a list of the Gundams)
Only two suits are known to use the Core Block System in the Correct Century: the WD-M01 Turn A Gundam uses a waist-mounted cockpit fighter, while CONCEPT-X 6-1-2 Turn X uses detachable head and body parts.
In the Cosmic Era, ZAFT uses a variant system, called the "Core Splendor System", for the ZGMF-X56S Impulse Gundam. This system is similar to the Victory and Victory 2's Core Block System, and is first tested out in the ZGMF-X101S ZAKU Splendor.
In the Anno Domini era, the modular Core Block System is first used by GNY-004 Gundam Plutone, which appears in the sidesstories, Mobile Suit Gundam 00P and Mobile Suit Gundam 00F, and later in the main anime series Mobile Suit Gundam 00 by GNW-20000 Arche Gundam and most of the GNZ series of mobile suits. The Innovators used the data from GNY-004 Gundam Plutone when developing these suits, and as a result most of them have a plug-in core fighter containing a GN Drive as the propulsion system. Variants of Gundam Plutone, Arche Gundam and GNX-803T GN-XIV equipped with such system also appeared in other sidestories.
- GNW-20000 Arche Gundam
- GNY-004 Gundam Plutone
- GNZ-001 GRM Gundam
- GNZ-003 Gadessa
- GNZ-005 Garazzo
- GNZ-007 Gaddess
- GNX-805T/CF GN-XIV Core Fighter Loaded Type
In the Advanced Generation timeline, the first mobile weapon to incorporate the Core Block System was the EFF's AGE-3 Gundam AGE-3 Normal: it used both a Core Fighter and the G-Cepter - a separate transformable unit capable of autonomous flight. This system was utilized in switching between the suit's armor wears, eliminating the need for the AMEMBO. Initially, both the Core Fighter and the G-Cepter require a pilot each for successful docking, but this is modified later and only a pilot in the former is necessary. The AGE-FX Gundam AGE-FX, on the other hand, uses the Core Fighter to simply attach to the back of the suit (rather than docking and combining with another module) to both operate it and serve as its main propulsion. The Xvm-fzc Gundam Legilis acquired the Core Fighter technology from the data taken from the AGE-3 Orbital, but its system function more like AGE-FX's than the AGE-3's.
- AGE-3 Gundam AGE-3 Normal
- AGE-FX Gundam AGE-FX
- Xvm-fzc Gundam Legilis