The canon content [Link]
The canon content of the Mega Man series is composed of all the games officially released by Capcom, along with the various licensed source books released in Japan over the years. Additionally, the extra content of the Rockman Zero soundtracks released in Japan, which expands on the storyline a bit, is also considered canon.
The TV series, mangas, games created by other companies (such as Rockman & Forte for the Wonderswan, as created by Bandai) and such are NOT canon, and they often contradict the information found in the games. Therefore, they can't be used in an argument related to the main material.
What about the remakes? Are they canon too? [Link]
This is a hotly debated topic. As of now, both Mega Man: Powered Up! and Mega Man: Maverick Hunter X, being remakes, introduced new plot elements that directly contradict some established facts.
There's no set or direct answer to this yet. Several people believe that, until the set of remakes has been completed (or at least features several games), that the established facts should be considered as the correct ones. Since future remakes sequels seem to be unlikely due to low sales, many people decided to stick with the already known details instead of taking into account the new ones.
The main timeline [Link]
The Mega Man video games can be regrouped in seven series that all have different characters and settings: the Original (or Classic), X, Legends, Battle Network, Zero, ZX and Star Force (in order of the first release). What could be called the main timeline goes as follows:
Original -> X -> Zero -> ZX.
The Legends series might be related to that, as taking place either in the far past or the far future; while the second option is somewhat likely, it hasn't been confirmed officially at this point.
The Battle Network series happens in a parallel universe, since it begins at the same time as the Original series (in 20XX). Star Force follows in that branch 200 years later. As such, we have:
Battle Network -> Star Force
The years of the in-game events [Link]
Some games directly name the year (or period) of the ongoing events, while others only imply things.
- The first three Mega Man games are all set in 200X, while the sequels (up to Mega Man 9) happen in 20XX.
- The Mega Man X series takes place in 21XX until the events of Mega Man X: Command Mission, the last chronological entry in the series, which happens in 22XX. We can assume that, because of the century change, this is early 22XX.
- The Mega Man Zero games, which all happen within a few months of each other, are set 100 years after the X series. This is usually believed to be 22XX (most probably later in that century), as the "100 years" reference was given based on 21XX.
- Mega Man ZX moves things up by a few hundred years, but without any specific year or decade mentioned.
- The Mega Man Legends series doesn't mention any specific dates.
- Mega Man Battle Network also happens in 20XX, as it's set in a parallel universe.
- Star Force, following 200 years later, is set in 22XX.
The color of Mega Man's eyes [Link]
This is easy to remember once you know it: the original Mega Man's eyes are blue, while the follow-ups (X, EXE and Trigger) are all green.
The colors of X and Zero's eyes [Link]
The colors of the eyes for both X and Zero tend to confuse people, including the various Capcom artists involved since they switched the colors around a few times by mistake (mostly in Mega Man X4). Mega Man X's eyes are green, while Zero's are blue. This applies to Zero in both the X and Zero series of games.
Mega Man and Roll: are they related? [Link]
In the original series, both Mega Man and Roll are robots created by Dr. Light. As such, they can be considered as brother and sister sharing a single "father". However, in the Legends series, Mega Man was adopted at an early age by the digger Barrell Casket, who happens to be Roll's grandfather. The two were raised together, but aren't related. In the Battle Network world, both are NetNavis built separately, so they aren't relatives in any way.
How to write -Man names [Link]
Mega Man vs MegaMan vs Megaman...
All of the names ending by -Man are written differently by each person. As such, several people hesitate about the proper spelling. As a general rule, it goes as follows:
Original series and follow-ups: Mega Man, Heat Man, and so on
Battle Network series and follow-ups: MegaMan, HeatMan, and so on (technically MegaMan.EXE and HeatMan.EXE, although most people decide to omit the .EXE suffix)
As such, the -Man part always has a capitalized M. The form "Megaman", used only a few times through the series, is incorrect in most contexts. As such, it should be avoided.
Future games [Link]
Capcom usually announce new Mega Man games only months before their releases, at least in Japan. As such, it's often difficult to know if a series has been left for dead or not. The following covers each series and gives it's current development status, in order of the first release.
Last main game: Mega Man 10 (2010)
Status: The very-retro Mega Man 9, released in 2008, put some energy back in the Original Series. Mega Man 10 was announced a year later, clearly showing that sequels can now come at any time. Mega Man Universe was in development for a year before being cancelled, and the status of any future games, including a possible Mega Man 11, is unknown.
Latest main game: Mega Man X8 (2005)
Status: The X series' releases have often been spaced out a bit, so a possible Mega Man X9 shouldn't be ruled out. A sequel announcement wouldn't be surprising to see, even if it takes some time.
Latest main game: Mega Man Legends 2 (2000)
Status: Mega Man Legends 3, after being announced in 2010, was cancelled unexpectedly. As a result, any development on the Legends series at this point is unlikely.
Latest main game: Mega Man Battle Network 6 (2006)
Status: The Battle Network series is the only one to have been officially concluded. Expect no future games to be released, outside of upgraded ports or remakes such as Operate Shooting Star (Japanese title).
Latest main game: Mega Man Zero 4 (2005)
Status: It can be safely assumed that the Zero series is over: the plot was concluded and it's development team moved on to the ZX games.
Latest main game: Mega Man Star Force 3 (2009)
Status: Currently on hold, as part of the team moved on to work on Legends 3 (which was later cancelled). Since Mega Man Star Force 3 wraps up the plot pretty nicely, it's possible that no new games will follow. Keep in mind, in any case, that nothing has been announced officially so far.
Latest main game: Mega Man ZX Advent (2007)
Status: No news about a future game have been given at this time, but a follow-up is possible.
The game that used to be called "Mega Man 9" or "Rockman 9" is actually Mega Man & Bass (Rockman & Forte), a game originally released for the SNES in Japan only. The game was released several years later on the GameBoy Advance in all territories. Many people used to refer to it as Mega Man 9, since it was the first original series platform released after Mega Man 8. Several ROM download sites also labelled the game as such.
The game itself has no references about being the ninth game, either on it's title screen or anywhere else. In fact, it's internal name is ROCK8.5, situating it between 8 and 9.
The confusion about this game ended with the release of the actual Mega Man 9 in 2008. The ending of that game references Mega Man & Bass, confirming that this new release takes places after the previous title in the timeline of the Original Series.
Does a Mega Man 9 or 10 NES ROM exists? [Link]
No. While the games look, sound and play like two NES games, there's no such things. Several components of the games, such as the downloadable content and the high scores lists, couldn't be done with the NES hardware. The IntiCreates team, who built the games, mentioned in several interviews that they used modern programming tools and structures instead of the more basic software available to create NES games.
As a result of all this, the games can't be put on a NES cartridge and played using the original hardware. Don't judge a book by it's cover!
Who is Reggae? [Link]
Reggae is the robotic bird seen if you enter a wrong password in Mega Man 7, or to annoy you in any way possible in Rockboard. The character originated from an old Japanese-only manga, where he served as Dr. Wily's pet bird.
Who is Tango? [Link]
Tango is just like Rush: a robotic assistant to Mega Man, although this one is a cat. The only game to feature him was Mega Man V, for the Game Boy. You could summon him to bounce around you, hitting enemies along the way.
The spelling of Dr. Wily's name [Link]
This is another of those situations where even Capcom makes errors confusing the fans: the last name of the evil scientist from the original series has been spelled either "Wily", "Wiley", or "Willy". The correct way to write the name is "Dr. Wily", as stated in most games and references.
The original Mega Man's buster [Link]
Mega Man has the ability to turn one of his hands into a blaster (often called the MegaBuster) to shoot at his enemies. Some people believe that it is the right hand, while others claim that it is the left. In fact, Mega Man has the ability to turn both hands into MegaBusters, even both at once as seen in SuperAdventure Rockman. However, this isn't something that he can usually do as it requires too much energy, potentially leading to his demise.
Is Proto Man evil? [Link]
Proto Man, built by Dr. Light, is Mega Man's brother. However, he isn't evil in any way. He acted the way he did in Mega Man 3 since he had never met Mega Man before, and as such considered him as an opponent. The "Mega Man" cartoon portrayed him as evil, but nothing from that TV show can be considered official (or canon) since the creators took several liberties with the original material.
Iris, seen mostly in Mega Man Xtreme 2 and Mega Man X4, was meant to be a part of the ultimate Reploid when combined with her brother Colonel. She wears the Repliforce logo, but was not part of their main operations. She originally trained with the Maverick Hunters as seen in Mega Man Xtreme 2.
Are X and Zero reploids? [Link]
By definition, a reploid is a robot based on X's design, originally through Dr. Cain's work. X can't be "based" on his design, since he IS the original model. As far as Zero goes, he was created by Dr. Wily decades before X was found sleeping in his capsule, so he can't be called a reploid either. Both are therefore robots.
Dr. Cain's situation [Link]
The last news from Dr. Cain comes from Mega Man X4's manual introduction, where he sent a directive instructing the Maverick Hunters to check on the Repliforce situation. While Signas, Alia, and Douglas took over his role in the games, the scientist himself is unaccounted for. A popular opinion is that he retired himself away from the messy world situation he contributed to create, although nothing officially confirms this yet.
The PSP remake Mega Man: Maverick Hunter X seems to be taking his story in a different direction. Even before the events of the game, his house (with him inside) gets hit by a missile, indicating that he might have met his end early on.