This is something I made out of boredom. I going to keep adding to it as things come to mind or if someone gets an idea they can add it themselves, and I will add to the author's list. 

I sort of made this guide so there can a centralized idea and understanding about how, at least my, reploids work and function. As I own no rights to any of this, you can use it as you please. I do not wish to force this guide upon anyone and simply state, "use it or don't, that is up to you" 

Either way just enjoy my little bit of fan obsession and again if you have any ideas on things to add, detract, or don't agree on, do not hesitate to say so. 

Guide to Reploids: Crimson Edition

This is mostly a work of boredom. I am not claiming this is the de facto anything to Reploids. These are simply ideas and assumptions I have had over the years. It is fine if you do not agree with everything as I am not the inventor of Reploids and am simply an obsessed fan.

For those of who know the Mega Man X Mythos we know how Reploids came to be. They were made loosely based off the design of Mega Man X. Which of course caused problems down the line as Cain was an archeologist and not a robot specialist. The series is very vague as to how Reploids work or their true capabilities. So it is generally up to us, the fans, to fill in the blanks. I will do my best to give my views and opinions on these blanks in as much detail as I can.


Reploids have a skeleton similar to human beings, however the biggest difference is the skeleton is made of very dense metal. It is hard to bend or break and gives reploid’s most of their strength, which means any muscle on a Reploids ‘skin’ is simply for show and has little to do with how strong they are. As well since Reploids lack certain organs humans do, such as lower intestine, liver, etc. their skeletons are mostly solid and have very few hollow points. The only worth while hollow point is where the core is located; it is suspended inside and not choked up by metal to give it some air to breath and not over heat. The skull is not hollow at all, it a dense mass of metal storing the CPU and what makes a reploid tick. More on that later. 

Because of the density of the skeleton Reploids can take more punishment and endure more than humans. Depending on model a reploid’s skeleton could allow them to lift armored cars or even tanks. Also a reploid can take a basic bullet without any true danger to its person, but a good shot of plasma or the right ammunition and they will be in danger. Also thanks to their structure they can fall from great heights without hurting themselves, of course there is eventually a point where a reploid is in danger of breaking its bone or even death. However the altitude is such for death the only reason a reploid would jump is suicide or being pushed, any other scenario is a rarity. 

Most Reploids also have issues in water, simply dropping like a rock till they hit the bottom. Reploids with the ability to swim have had their structure hollowed out for flotation, added a propulsion system to their bodies or have their bodies made out of less dense metal, which of course trades off to a weaker frame.


Yes, Reploids do in fact have organs; at least I believe they do. One of the most important is the core, which is basically a Reploids heart, pumping energy through their bodies and allowing them to function. Most of the cores run off of solar energy, the most abundant energy source, and if the sun is not available then most cores can last one to two weeks without giving out. Now with this knowledge it is curious why a reploid would need to sleep. My hypothesis is even if outside a reploid is still using power while charging, much like using a cell phone or laptop while it’s still plugged in. So a reploid will never be able to be at hundred percent while active, and has a greater chance of feeling what humans call fatigue. As such they ‘sleep’ so they can get a hundred percent charge and feel fully ‘rested.’ Now as most Reploids don’t sleep outside, mostly because of the dangers it presents, they either sleep in energy capsules or with a mobile recharger. 

Along with the core Reploids also have a ‘stomach’ of sorts, which allows them to eat and drink normal human foods. A reploid has no need for calcium, sugar, or any nutrients so the process to break down the foods isn’t exactly complicated. If it is a solid, the stomach will warm up and churn the food until he becomes a liquid state, at which point it will be fed into the core, giving the reploid a quick boost of energy. It is much like squirting lighter fluid on a fire, it gives a quick boost and is quickly burnt out, but in a pinch a reploid can eat meals to keep alive, however they must eat more than humans and at least six times a day. 

Reploids who wish to look like humans generally have a layer of skin over them, which a lot of the times out of their armor they can be mistaken for human, as it looks feels and reacts much like normal skin would. The skin is kept alive but a liquid which come from the core and circulates throughout. The liquid is not normally red, much like a humans isn’t till it reacts with oxygen, but it is dyed so to keep up with the illusion of humanity. The skin is also attached to sensors all along the outside of the skeletal structure, which acts like a nerve system, so a reploid can ‘feel’ when the skin is touched, cut, or hurt. 

The second most important ‘organ’ to a reploid is its brain or CPU. Its personality its memories are all stored within it. Now the brain brings across the question if a reploid is truly ‘alive’ or not as they do not carry what humans call souls. As well their emotions are technically created by programs and software to help them emulate humanity and their emotions are not technically ‘real’, and unlike human beings they can simply shut down their emotions.  Also within the brain is the option to shut off the sensors around the skeletal structure so they can be worked on without feeling pain, but remain conscious. 

Depending on model there is an access point on the back of the skull for software repair and work, which can either be opened by the reploid remotely or if the reploid be unconscious be lifted open by tools. 

Also, depending on model, the head is also the location of any communication unit which a reploid can mentally access the array and is far more efficient than the hand held radios that humans have used over the years. 

The only hollow part of a reploid’s skull is where the eyes are located; the eyes are oval shaped metal orbs with lenses covering the cameras to continue the human emulation. Much like a human brain the eyes are connected to the main CPU and whatever the cameras pick up are recorded and stored simultaneously. 

Now this section was brought up with curiosity, the idea of a reploid being able to reproduce. Now, the overall need of a reploid to give birth or need to give birth to another is pointless, as if two Reploids fall in love they can build a child. Now when you think of the idea that since some Reploids wish to emulate human beings, than it is an inevitability that a human and reploid will fall in love. So, Reploids are given their options: They can have sexual organs simply for pleasure or for the purpose of actually giving birth. This cannot be called natural, but it has been contemplated with the use of nano-machine that carry what would be the ‘dna’ of the reploid would allow for children to be birthed. Allowing for a child bearing both traits of the reploid and human parent; however the child will be human, as the biological growth of Reploids is still plenty far off. 


One of the main ways to differentiate Reploids from humans is their armor. What type of armor a reploid has is based on what they were made to do and whether not they wish to emulate humanity.

A ‘civilian’ type reploid will be given a much lighter armor and tools which will be related to that job in hand. The strongest armor given out is ones for construction, but it is still not as strong as the ‘Hunter’ armor permutation. The Hunter armor is made purely for combat and typically the Reploids who use this armor designate themselves for the more permanent armor which is stronger and thicker than the removable type. 

Both types are also highly customizable, given just a basic outline they can be upgraded well beyond their normal means, the only limitation is how much energy the reploid’s core can output. 


Mentally a reploid ages very similar to a human being, though the difference it is ‘born’ with the kind of mental understanding of the age it is supposed to personify. For example a reploid designed with the mental state of a twenty year old will understand how to drive, use appliances, operate machinery, etc. Though a Reploids personality is not defined at this point, much like a human being its experiences help define its personality. It is not programmed with a personality, of course there can be nudges in directions, but the same can be said with raising human children. 

Now physically a Reploids body does age, but only through basic wear and tear like any kind of machine, having to repair themselves and keep themselves up to date. Now their outward appearance doesn’t have to change at all, they can simply look the same throughout their life time, but if they wish they can have their bodies modified through the year to give the appearance of age. 

Now there are hypotheses that Reploids can live forever with repair and upkeep. After all X lives for nearly three hundred years in the same body, though of course this could be contributed to the fact Dr. Light was a robotic genius. There is little to either confirm or disprove this fact, the only real ‘proof’ is in the character Prairie who is heavily believed to be Alouette from the Zero series and that she would be nearly one to two hundred years old, and didn’t have any significant creator to be mentioned.


Reploids have well above human strength; even ‘civilian’ type Reploids can lift at least a ton. It is my opinion that most of a reploid’s strength comes from the skeletal structure. A reploid’s armor is simply for protection, a little more oomph to CQC, and a place to store weapons, tools, etc. Now ‘Hunter’ reploid’s possesses immense strength, able to lift armored cars and tanks, though the latter with a bit of effort. Where a civilian could punch a concrete wall a Hunter could imbed its fist into a steel slab. Also Reploids have much greater stamina as well, though just like anything attrition will eventually wear them down and their cores will redirect energy to more critical systems. 


Maverick (イレギュラー Iregyurā?, Irregular in Japan) is a term given to Reploids and Mechaniloids that are a threat to humans, which can be caused by errors, viruses, reprogramming, or even by their own free will upon deciding that humans are too weak to live (or some variation of this thought).

That is the definition of Maverick by MMKB (Mega Man Knowledge Base). As most reploid’s infected by viruses go maverick, it has been thought that all mavericks are in fact viral, which is not the case. However as that would detract from this section I will simply keep to the viral form of maverick and perhaps leave any other form up for conjecture.

Viruses affect reploid’s personality and attitude, regardless of past events or life experiences, guiding the reploid to do as the virus intended. Like a computer virus it is attempting some form of negative result, perhaps simply recording or tracking a reploid’s where about, much like a key logger tracks whatever keys you have pressed on your keyboard to track your internet movements and information. Though the more extreme viruses wish to bring the reploid’s mind into chaos and cause instabilities leading it to become a danger to itself and all who are around it. Just like any virus it can be wiped and cleaned, but if left too long it can cause lasting effect to the Reploid’s CPU, such as in violent situations a reploid may lose control of themselves, which can be related to human mental conditions.