RKC (File Format)

RKC Files are files downloaded by Mario Kart Wii using the WC24 download engine. The RKC file contains data and an SZS file with a new KMP for the competition. The RKC file is part of the DISTMAP.BIN file, which is stored inside the wc24dl.vff file in the savegame.

Known editors:

• RKC Editor by Leseratte

Header

The RKC Files contain multiple headers, they are all explained here.

RKCT

The RKCT, or main header, is 0x10 in length.

Offset	Type	Description
0x00	char[4]	'RKCT' in ASCII; File identifier
0x04	int	Length of the data in bytes.
0x08	int	Length of all file headers. (offset to the beginning of the Yaz0 file)
0x0C	int	Unknown (always 0x640 = 1600), maybe a version number?

RKCO

The RKCO Header contains all information for the competition. Stuff like course id, CommonObj that gets loaded and other information. This header is 0x3C in length

Offset	Type	Description
0x00	char[4]	'RKCO' in ASCII; File identifier
0x04	short	Game mode - laps or points. Possible values: 0: TT without CPU, 1: TT with CPU, 11: VS without CPU, 12: VS with CPU, 3: many different objects, see the list below, 4: Spikey Topmen, 5: Coins, 6: Stargates
0x06	byte	Course ID
0x07	byte	Engine class. 0: 50cc, 1: 100cc, 2: 150cc, 3: battle
0x08	byte	Amount of laps (laps, so triggered with checkpoints, not scores)
0x09	byte	(always empty, unused)
0x0A	short	Vehicle restriction (0: karts only, 1: bikes only, 2: no restriction)
0x0C	short	Camera angle (3: normal camera, 7: camera from above)
0x0E	short	Minimap object. Defines an object to be shown on the minimap
0x10	short	(always empty)
0x12	short	(always empty)
0x14	short	Cannon flag. If a track has no cannon, this is set to 0. If a track has a cannon and its setting is 0xffff, it is set to 0, too. Otherwise, it is set to the value of the cannon setting.
0x16	short	Amount of CPU players
0x18	short[11]	Driver and vehicle settings for CPU players. First byte driver, second byte vehicle. 0xFF for random driver / vehicle or unused slots
0x2E	byte	Controller. 0x00 for "free choice", 0x01 for "Wii-Wheel-only"
0x2F	byte	(always empty, unused)
0x30	short	Common object files to load. Bit field for the different files.
0x32	short	Score (amount of gates, amount of coins, ...)
0x34	byte	Intro settings. Between 0x00 and 0x03, 0x00: no intro video
0x35	byte	(always empty, unused)
0x36	short	Unknown, either 18,000 for tracks with laps, or 36,000 for tracks with a score. Not used by the game
0x38	short	(always empty, unused)
0x3A	short	This seems to be a checksum.

Game mode 3 is interesting; in this game mode, many different objects give you a point when you destroy / hit / activate them, including the following:

• Goomba
• Crab
• Cataquack
• Monty Mole
• Leaf pile
• woodbox
• The bats from Warios Gold Mine
• Bomb cars (no normal cars!) from Moonview Highway
• Pokeys from DS Desert Hills / Dry Dry Ruins
• and probably some more which I forgot

There are a few more game modes (the ones which do not appear in the list of game modes above), but their meaning and usage is unknown.

RKCS

This is the part of a RKC file that contains the actual data. It only contains a Yaz0 compression (SZS file) of a KMP file and some object files which are neither in the course the competition bases on nor in one of the CommonObj files.

This SZS file *must* contain the folders "AIParam" and "ItemSlotTable", but both of them may be empty if you do not want to modify the AI settings or the items.

The KMP file of the competition has a few interesting things:

• Not all sections are included (if there are no CPU players, there is no need for CPU routes), if there are no items, or at least no bullet bill and no red shell, the item routes may also be missing.
• The MSPT section is included (stop point) and may have multiple entries
• There can be multiple start points, like in a battle.

Replacing and ripping RKC files

NOTE: The data blocks which were previously known as "RSF Files" (this name was invented by khacker35000vr to name unknown data groups) are NOT part of the actual competition. If you extract the VFF file and not just open it in a hex editor, you can see that there is no data after the RKC file. The "trash data" (RSF) in the VFF file after the RKC data is just random data from the previous competition, because Nintendo just copies the new RKC file to the specific offset and does not clear the rest of the file. So, when a new competition is smaller than the old one, those trash bytes stay in the file even when they are not needed.

Replacing

• Search the RKC file in the VFF File.
• Copy and paste (overwrite old data) the data of your custom RKC file at the good offset
• If the new RKC file is larger than the older one this may not work, but at the moment there is no tool to create larger VFF files.

Ripping

• Use riivolution along with the savegame xml when a competition is in progress, or copy your savegame to SD with tools like the Savegame Manager GX
• Extract the wc24dl.vff with "vffdump.py".
• Open the file "DISTMAP.BIN" in a hex editor and search for "RKCT"
• Check the size and copy that amount of bytes to a new file (RKC)

Misc.

• Custom tournaments are not a very popular thing, only Vulcanus2 succesfully made a custom tournament and probably only a few others have played it.
• All downloaded contents (competition and other players' ghost data) for Mario Kart Wii are saved in wc24dl.vff.
• It is unknown if wc24dl.vff is a distributable file.