In the near future, everyone has a personal exploration terminal (PET), and the hero Lan has MegaMan.EXE as his. Together, they stop cyber crimes, eventually discovering WWW (World Three).
This game completely ditches the previous Mega Man platformer gameplay and instead is an RPG, where Lan gives Battle Chips to MegaMan who uses them for special moves. The combat is real time and the enemies are viruses.
Mega Man Battle Network is later ported into the Nintendo DS in 2009, titled Rockman.EXE Operate Shooting Star. This port adds several new features, particularly a crossover scenario with Megaman Star Force and is unreleased outside of Japan.
This game provides examples of:
- Accidental Public Confession: Mr. Match accidentally reveals that the serial arson he engineered was actually all about getting the Fire Program in Lan'snote oven when he consoles himself over his loss by mentioning he "completed his mission". He immediately realizes he probably shouldn't have told Lan that.Mr. Match: "But who cares! Soon war will start and you'll all be dead!"
- Early Installment Weirdness: The first Battle Network is not only an Obvious Beta, but it was still trying to figure out how to hash out the world itself.
- In this game and 2, Navi Cust doesn't exist, instead they have Powerups that only upgrade MegaMan's buster.
- HP values for enemies were much lower in the first two games. With the Navi Customizer comes massive HP spikes for both players and enemies.
- Enemies (especially enemy Navis) become faster as the series goes on. In the first couple of games, the flinch that enemy Navis perform when they take a heavy hit is exaggerated and they only remain in Mercy Invincibility state for a few seconds (if even that); by 4, their flinching and Mercy Invincibility lasts about as long as MegaMan's.
- There was also a general willingness to be more sexually explicit in the early games. In the first game, you can walk in on Mayl changing clothes or discover Dex has a Porn Stash.
- Lan is much snarkier than his later Idiot Hero selfnote , and Dex refers to GutsMan as a commercial model.
- The main internet area looks very different than it did in later games — it's a mostly-incomprehensible maze with a few chip salesmen scattered over it and no real pattern to it, whereas later games tended to make it much more orderly and distinct for each region. Indeed, because the first game had the same background for all parts of the Internet, it's impossible at a glance to tell the difference between the "regular" Internet and the Undernet.
- Elemental Armors. While it may serve as the precursor to the Style Change mechanic, it functions differently; you can buy them from Net merchants, it halves all damage that isn't the armor's elemental weakness.
- Viruses are not named during battles, and Ms. Mari calls the Mettaurs "Mettools", as in the Classic series. Viruses that never appear again in later installments have their names only mentioned in the artbook.
- Chip Traders don't autosave.
- Escaping battles strictly requires the Escape chip. 2 introduces the L button as an escape option but retains the chip while the next game removes it completely.
- The existence of After-Combat Recovery, where MegaMan will recover all of his HP after every battle. The only exception is the Power Plant where it was presented as a one-time gimmick for the dungeon.
- Establishing Series Moment: MegaMan's attempt to pass through the oven's cyber-world is impeded by a field of flames. Lan clears the way for him by spraying the real oven in his house (which is also on fire) with a super-soaker. This works.
- Foreshadowing: As soon as you can use the Metro, you're prompted to pay Dad Hikari a visit at work. He's not in, but while you're at the office you can find a photo of his family revealing that Lan is not an only child, and talk to some Navis in the large workstation who tell you about an experimental Navi with human genetic data.
- Guide Dang It!: Locating the Undernet memos near the end of the game. The first one is easy enough to find, but the only hint you're given on the other two is that you need to find "a young beautiful lady and an old man". Never mind how vague this is, the lady is in a school in Dentown that you probably didn't know existed until this quest. To rub salt in the wounds, once you've found her, she won't give you the memo unless you've filled out enough of the Library. Hope you've been diligent on S-ranking battles! These memos are needed to progress in the story, too.
- Mercy Kill: The altered Programs in the first game's Power Plant dungeon have been irrevocably ruined by the WWW, some driven crazy, all turned into viruses. There's no way to save them from this, and so one of the sane programs asks Mega to kill them.
- No Endor Holocaust: An attack on the city driving system causes a series of wickedly violent car crashes. Beyond the spectacle of the crash itself, the game studiously ignores what should rightfully be devastating wreckage and a huge death toll.
- No Fair Cheating: Hacking will cause an impassible stream of water to bar Mega's entrance to the Waterworks dungeon, requiring a total reset of the game.
- Obfuscating Insanity: There's an old man NPC who spends most of the game telling you he's not senile. He's the one who knows how to access the Undernet.
- Perfect-Play A.I.: Invoked with ProtoMan. Official NetNavis can carry their own Battle Chips and battle without Operator input; according to ProtoMan, solo-fighting was his standard operating procedure, which fact combines with his "untouchable" reputation to form this trope.
- Sequel Hook: The end reveals that Wily is still alive in the credits.
- Take That, Audience!: An NPC Navi, located at the farthest reaches of the internet (which requires an extent of completion to reach) expresses this:"So you've made it this far... It's a shame you're wasted on the outside world..."
- Understatement: Wily drops this line while brainwashing an entire classroom of children."To reach our goals, the WWW is hiring new staff members!"