What is a 3DS Rom header?

Discussion in '3DS - Flashcards & Custom Firmwares' started by EpicLink, Mar 4, 2015.

  1. EpicLink

    EpicLink Newbie

    Nov 29, 2014
    United States
    Whats a 3ds rom header? and how does it effect online games.

    Considering getting a gateway card and heard about rom headers, not exactly sure what it is...
    I hear you can transfer a rom header from ANY game to anther? including from non online games.

    also any tips on the subject?
  2. MattKimura

    MattKimura 3DS & WiiU Enthusiast

    Jun 30, 2014
    United States
    you need headers to play online. Without it, you'll have no unique ID when going online.
    You can't go online without a header, you need that unique ID so that you'll show up as something other than an invisible blank ghost.
    Sky3DS users don't have a way to dump headers like Gateway users can. They have to rely on 9.0 3DS to use the Gateway exploit. You can borrow a friend's 3DS to use it for this if they're still on 9.2 or lower.
    Gateway is the same, you need a header to play online and they have it quite easy to patch their games.

    The headers can be of any one game. You can then use that one header for all your online games. The purpose is to not go online with the same header more than one at a time. So using your own header guarantees that only one of that header will go online. Just keep the game you use for it's header and never get rid of it or let anyone go online with it at the same time as you.
  3. apoptygma

    apoptygma GBAtemp Advanced Fan

    Mar 30, 2010
    People use the terms header and unique ID interchangeably but they aren't the same thing. The header is like a table of contents which contains things like the rom title and size as well as the unique id, which is like a serial number.
    MattKimura likes this.
  4. StriderVM

    StriderVM GBAtemp Fan

    Jan 16, 2015
    I would compare header for a 3DS ROM like a "serial number" for a game. So makes it every copy of a game are unique, can be traced, and can be used as an authentication procedure.

    It's a good guess that Nintendo is using the header of a 3DS going online to see which 3DS units are using a single header, and may be banning the consoles.
  5. xile6

    xile6 GBAtemp Maniac

    Jan 15, 2006
    United States

    so i admit that i dont know much about the headers. Im coming from old school gba and stuff.Thats when i was around lol.
    this 3ds and encrypted stuff is a tad weird to me. (i understood the playstation stuff tho)

    So lets see if i understand this.
    Each game cart is giving a different CardId?
    So if i had 2 copies of SuperSmashBro they both would have different ids correct??? as in 1 could be 0001 and the other 0008

    So if nintendo see that cardID 0001 is online on two different system at once, it would flag it in the system.

    With no header it would show up and user XXX playing BLANK since there is no cardID. and the system would flag that due to it being and error.

    So what we would want to do is copy the cardID from an old game and inject it to all the roms on your sky3ds.
    So when you go online it will display that your online playing that old game and nintendo system will think everything is ok?

    Someone please correct me where im wrong. i am trying to get and understanding of all this.

    Also do these header effect save data? I would love to tranfer my original cart saves to the sky3 roms
  6. StriderVM

    StriderVM GBAtemp Fan

    Jan 16, 2015
    If the game has no header and you go online with it, online will boot you out.

    Yes, your understanding of it right now sounds correct, and a lot of people have actually done the thing you're thinking of. In theory as Nintendo only, the best we can get is speculation using what is currently available information.

    As far as I know, save data is not affected by it's header.
  7. Jiro2

    Jiro2 GBAtemp Advanced Fan

    Mar 28, 2011
    United States
    Actually, I thinl that changing the header does affect your save data. You'd need to use SaveDataFiler to keep using your save, which can get complicated.

    Also, there were recently some online bans by Nintendo. Everyone who is known to have gotten a ban was using a public header. So some people feel it is not safe to use public headers. This doesn't mean you're completely safe if you use a private header since it's likely Nintendo can detect more things if they tried harder, but so far private headers have not led to any problems.