Trivia: Mega Man Zero

  • Jossed: At the time there was a popular theory that the Mother Elf was originally a reploid (more specifically Iris from X4) based on the fact that X and Elpizo underwent a similar transformation. This theory was officially disproved in Complete Works where is stated that the Mother Elf was created from the Maverick Virus data in Zero's body.
  • No Export for You: The e-reader bonus content for the original GBA Zero 3 (Averted for the DS Compilation Re-release). It can be nevertheless be enabled in non-Japanese versions via cheat codes, complete with english text.
  • The Other Darrin: Both Zero and X have new voice actors that were never used in the Mega Man X series; Zero is played by Ryōtarō Okiayu in X and Yuuto Kazama in Zero, while X had been played by Showtaro Morikubo up until X7 and is played by Takahiro Mizushima in Zero. Notably, the X series continued using Okiayu for Zero and diverged into a new example of The Other Darrin for X by introducing Takahiro Sakurai to the role instead of adopting the Zero series' actors.
  • Postscript Season: The series was meant to end with Zero 3, as evidenced by resolving the Dark Elf storyline, giving X his eternal rest, bookending with the lab ruins, etc. And developer interviews. Of course, all good things must never come to an end as far as Capcom's concerned, so we got Zero 4, which turned a Postscript Season into a proper Grand Finale.
    • Strangely, the fates of the three living Guardians after Omega's death are completely ignored until the Zero Complete Works, which says they died in Omega's explosive death throes. Z4 doesn't so much as mention them.
  • What Could Have Been:
    • Zero 1:
      • The original X himself was going to be the Big Bad, and not just some copy. Presumably after having to deal with the maverick uprising all by himself for over a hundred years, he would have snapped and Jumped Off The Slippery Slope in the name of protecting humans. The Big Bad being a copy instead was literally a last month decision, and done because it was felt X being a canon Ron the Death Eater wouldn't sit well with the kids who played the X series games where he was the hero.
      • Ciel was originally drafted as a cyborg.
      • "Harpuia" was originally meant to be the name of the character's swords.
    • Zero 2: A bat-like One-Winged Angel form was planned for Phantom to match the other three Guardians', although considering that Phantom had already been killed off, it may have simply been drawn on a whim. See here.
    • Zero 3:
      • Young, middle-aged, and elderly (i.e. the final version) designs were drafted for Weil. The young version had a Mini-Mecha.
      • Omega's second form would have been much more active (for example, actually using its BFS) if not for GBA's graphics limitations.
      • The series was originally meant to end with the third game, with Dark Elf now free, X finally retiring into Cyberspace, and Omega being destroyed for good. Thankfully, they changed the Post Script Season that is Zero 4 into an epic Grand Finale (though with some Fridge Logics here and there).
      • The bad part about that: The 3rd game actually left a good hook for Mega Man ZX, which caused the for the most part happy ending of the 3rd game to be overridden and retconned the previous ending to kill 3 major characters offscreen.
      • Volteel Biblio's design is adapted from an older design for a electric eel boss.