This is for my forging the future AU-- note that I have a TON of freelance work nipping at my heels, so, this may not be completed quickly. It includes a lot of fluff, but I figured it would work better consolidated instead of putting it in the main thread and having people bouncing back and forth. Lemme know if people think that should be changed:
Protomechs and the Clan Wars
Protomechs were actually developed right before the fall of the star league. In fact, it was the restive nature of the periphery that lead to their initial development, as the Star League attempted to develop methods to engage dug in forces in cities that did not (always) result in the destruction of said cities. The protomechs were to be part of an integrated combat team, including light powered armor and drone combat units, enabling the Star League to make use of its technological supremacy.
But the design floundered, and difficulties with the cybernetic control systems resulted in several test pilots dying, or suffering...unfortunate side effects. Other forces conspired against it, as many generals, still smarting over the transfer of funds to the CASPER systems, opposed such "frivolous" use of funds, arguing that the best way to subdue a city was to send a regiment of assault mechs in.
Work continued, but ceased with the Amaris coup and the new "emperor" was even less enamored by small combat systems than the SLDF had been. The designs ended up mothballed, sitting in warehouses with their manuals neatly stacked beside them-- even Kerensky overlooked them.
And there they sat, for many years, until 3052, when sheer panic gave the Comstar/PSDF/Successor State alliance a certain impetus to find something-- anything that might turn the tide.
by 3052 the Clans had conquered Tharkad, smashed Hesperus II's defenders and taken them and were threatening Luthien. Deep raiding Clan forces had savaged many combat formations before they even realized they were being invaded. The Warship forces of the Inner Sphere, mostly Comstar and PSDF were hopelessly outnumbered by the Clan forces, and the Clans had made themselves clear that any attempt to use orbital bombardment would be met with overwhelming retaliation. Deep penetration raids against Clan shipping were helpful (and the Clan naval forces welcomed them, as it let them have some of the fun).
But even so, the pause in 3052 had little to do with the Inner Sphere's defense and far more to do with the fact that the Clans had drastically overestimated how successful the Inner Sphere would be, and had not planned for such a fast advance. Even so, it was expected that by 3054 at the latest the advance would resume.
It was during this time that a number of researchers discovered the Protomech project. the Star League era design files could be used to produce new designs, and more importantly, while complex, they were within the capability of a number of factories. In fact, due to the smaller frames and the advantages of a more compact design, weight by weight they were nearly as effective as Clan frames, though their weapons were less effective, of course.
But most importantly, protomechs could be fielded in large numbers, and produced (or at least assembled) in relatively small facilities that would avoid the fate of the Defiance factories-- that could even be made more or less mobile, a point of some note if as many feared, the Clan invasion ended with the House's forced to fight an insurgency.
Finally, after some study by the best in the field, it was determined that the mental issues detected by the early researchers could be solved-- eventually, by a number of techniques. However, in the short term, by performing the operation on individuals between 15-17, it was believed that the worst of the effects would be eliminated. Covertly, several researchers also pointed out that even if they weren't, it would maximize the usable careers of these soldiers. The equipment itself was identical to the VDNI systems being prototyped and could even use the same style interfaces.
The innersphere, and for that matter the Periphery (which had its own opinion about legions of genetically engineered warrior's speaking of restoring the Star League) had no lack of volunteers. Lent urgency by the ever increasing chance the Clan's would advance once again Dozens of protomech factories were established. Protomech designs ranged from the 4 ton Infantry support unit to the Ultraheavy Dragon protomech.
When the clans resumed their offensive in late 3054, they were caught off guard. Their own intelligence had assumed that the new units were simply large battlesuits and the presence of protomechs that could kill light mechs, even clan mechs, caught them completely off guard. Suddenly, energy armed guerrilla protomech units were popping up on dozens of worlds, not least several regiments worth that were dropped on Tharkad, forcing Clan Snow Raven and NovaCat to divert forces intended for further offensive operations to try and pin down the maddening protomech forces.
Of course, the battles were not one sided-- the stories of protomech units dropped on worlds, in many cases with no back up, expected to fight to delay the clans until they were destroyed, became a part of the lore of the Inner sphere. Depending on who one asked (and opinions were divided on both sides) they were either patriots or naive cannon fodder, sacrificed by the Cynical House Lords. Many of the brave youths that marched onto their transports to cheering crowds would, by the 3060 truce, be bitter and cynical soldiers who had far too many ghosts living behind their eyes.
Nonetheless, the protomech and battlearmor forces flung into the fray in the 3050s provided the Inner sphere the time it needed to regenerate its savaged mech units, which were able to block the Clan offensive long enough for the Truce of Terra to be signed. The protomech forces would also play a major role in the 3063 Terran revolution and the subsequent founding of the Terran Union.
A few rules notes:
Most protomechs are largely constructed with the same frame and engine as clan units-- the assumption here is that much of the "efficiency" of protomechs isn't just due to super materials but because you have a more compact, smaller unit. However armor uses the Inner Sphere rules on the IS protomech thread-- the Clan armor is better. Also, inner sphere weapons are used as given in that thread. Some proto's do mount clan weapons-- it was possible to outfit an entire platoon of protos for the cost of a single mech and you were less likely to lose all of them at once, so as clan tech was obtained, protomech units, especially elite units, like Yvonne Steiner-Davion's regiment (later in the decade), tended to have a fair amount of clan tech.
Secondly, there are two types of protomechs-- the first designs used the neural interface system we see in canon. A later model made use of advanced VR control systems that didn't require a neural interface, being essentially a very large battle suit control system. This system weighs the same as its companion, but it requires the proto have the following changes:
piloting skill rolls are required for the same reasons on mechs, and that the "near miss" results on the hit location table are ignored and re-rolled. (This is stolen from Cray's nomad mechs).
The comstar/Inner Sphere forces have access to all sizes of protomechs, including ultraheavies.