When Rockman EXE and Ryuusei no Rockman were localized to places like North America and Europe, some content was removed or made inaccessible. There are actually quite a bit of changes such as removed scenarios, battles, viruses, all sorts of things. So if you have any questions about removed content, you can refer to this page.
Mega Man Battle NetworkEdit
Mega Man Battle Network 2Edit
Ubisoft published Mega Man Battle Network 2 in PAL regions, in the start up screen of the PAL versions Ubisoft are credited (this doesn't effect speedrunning as time begins when you hit start). However, this appears to be the only battle Network game Ubisoft helped publish. Nothing else in game is changed. Capcom also held events to give away "Gospel chips" these are some of the most powerful chips in the game, but Capcom never held any events outside of Japan making these chips impossible to get elsewhere without cheating.
Mega Man Battle Network 3Edit
Animations such as the jack in animation and NaviCust animation were removed from the North American and European releases. In Japan BN3 also came in 2 different versions, one just called Rockman.EXE 3 and the other being Rockman.EXE Black. The EXE 3 Black version was a re-release of the game with modified shops and fixed encounters as well as fixed bugs with the original. EXE 3 is equivalent to BN3 White and EXE 3 Black is equivalent to BN3 Blue.
Mega Man Battle Network 4Edit
Mega Man Battle Network 5Edit
In Japan there was an accessory called the Chip Gate, EXE 4 used the device as well. The use of the device would give you the upper edge in battles with the ability to slot in physical chips to give to Rockman and his friends. As well as the ability to switch out Navis. The Chip Gate never came out in outside of Japan so the features had to be removed from the game. Though if you import a Chip Gate, you can still use some of the features in a North American and European copy. You can also access the real time operating battle menu which is fully translated. The features included with the Chip Gate were added to the DS remake, BN5 Double Team DS.
Mega Man Battle Network 6Edit
The most common example of localization differences lies in BN6. The post game content consisting of the Boktai crossover was removed from every other version of the game. Meaning if you want to do the crossover scenario, better buy a copy of Rockman.EXE 6 from Japan. The Crossover Battle system was also removed because of the lack of Boktai 3 being available in North America and Europe and the time.
Mega Man Star ForceEdit
Unlike the North American and Europe releases, Ryuusei no Rockman lacks the Cipher codes which are typically used in a speedrun. Most bosses also have more HP in the original Japanese version. There are also smaller changes such as Libra Balance SP needing you to be in critical to encounter him. The NA and EU releases are basically the easy mode versions of the game. The Blue Wave Data was also rearranged in the localizations of the game making it more out of the way to acquire the same data in a run of Ryuusei no Rockman.
Mega Man Star Force 2Edit
In the European release, the Wave Command screen was removed for unknown reasons. Making it impossible to access Tribe King without using all 3 Tribe On powers and removes the ability to use Rouge. Through the use of hacking, you can get a blank card and use the Wave Command to get a card but said card will crash your game when used.
Mega Man Star Force 3Edit
There was no European release of Star Force 3. The US version lacks "noise cards" that were featured in the Japanese version. It is unknown why this feature was disabled in the US version, however they can still be accessed through action replay codes.