S>C 0x06 MCP_GAMEINFO

Transport Layer:Transmission Control Protocol (TCP)
Application Layer:Diablo II Realm Messages (MCP)
Message Id:0x06
Message Name:MCP_GAMEINFO
Direction:Server to Client
Used By:Diablo II, Diablo II Lord of Destruction
Message Format:
(does not include protocol header)		 
  (UINT16)     Request ID
 (UINT32)     Status
 (UINT32)     Game uptime (seconds)
  (UINT8)     Level restriction level *
  (UINT8)     Level restriction difference *
  (UINT8)     Maximum players allowed
  (UINT8)     Number of characters in the game
  (UINT8)[16] Classes of ingame characters **
  (UINT8)[16] Levels of ingame characters **
(STRING)     Game description
(STRING)[16] Character names **

Remarks

Information about a specific game. The game client requests this when a game is selected in the list.

Status is usually a set of flags about the game. If it is 0, the packet contains no useful information and the server is probably down. If it is 0xFFFFFFFE, the request was not valid.

Flag values (OR them together), if valid:

  • Difficulty:
    • 0x0000: Normal
    • 0x1000: Nightmare
    • 0x2000: Hell
  • Type:
    • 0x200000: Ladder
    • 0x100000: Expansion
    • 0x800: Hardcore

* The level range shown in game is calculated from the level restriction values; level and difference bytes are used to make the range max(1, level - difference) to min(99, level + difference).

** Internally, there are 16 character slots, but the last 8 are always empty.
This value sometimes includes some empty character slots.
Then, some empty strings are added to the end of the packet.
To determine the number of characters really in the game: 

CharsInGameReal = CharsInGameFake - AmountOfEmptyCharNames;

Byte N here refers to character in slot N, or 0 if the slot is empty.

| Edited: Anonymous

Comments

Kaylin

The game status field indicates the game type and difficulty associated with the game. The following return values were observed consistently on both USEast and USWest realms. 

Non-Ladder Softcore Expansion (Hell)     : 0x00102004
Non-Ladder Softcore Expansion (Nightmare): 0x00101004
Non-Ladder Softcore Expansion (Normal)   : 0x00100004

Non-Ladder Hardcore Expansion (Hell)     : 0x00102804
Non-Ladder Hardcore Expansion (Nightmare): 0x00101804
Non-Ladder Hardcore Expansion (Normal)   : 0x00100804

Non-Ladder Softcore Classic   (Hell)     : 0x00002004
Non-Ladder Softcore Classic   (Nightmare): 0x00001004
Non-Ladder Softcore Classic   (Normal)   : 0x00000004

Non-Ladder Hardcore Classic   (Hell)     : 0x00002804
Non-Ladder Hardcore Classic   (Nightmare): 0x00001804
Non-Ladder Hardcore Classic   (Normal)   : 0x00000804

Ladder     Softcore Expansion (Hell)     : 0x00302004
Ladder     Softcore Expansion (Nightmare): 0x00301004
Ladder     Softcore Expansion (Normal)   : 0x00300004

Ladder     Hardcore Expansion (Hell)     : 0x00302804
Ladder     Hardcore Expansion (Nightmare): 0x00301804
Ladder     Hardcore Expansion (Normal)   : 0x00300804

Ladder     Softcore Classic   (Hell)     : 0x00202004
Ladder     Softcore Classic   (Nightmare): 0x00201004
Ladder     Softcore Classic   (Normal)   : 0x00200004

Ladder     Hardcore Classic   (Hell)     : 0x00202804
Ladder     Hardcore Classic   (Nightmare): 0x00201804
Ladder     Hardcore Classic   (Normal)   : 0x00200804

In order to decode a successful response interpret it in the following way:

The game difficulty is this one of:

Nightmare : 0x1000;
Hell      : 0x2000;
Normal    : 0;

The game type is the bitwise or of any of:

Ladder    : 0x200000;
Expansion : 0x100000;
Hardcore  : 0x800;

bitwise or the difficulty with the game type and the number 0x4 to get a successful status response.

Other than the documented 0 response above, the server also returns 0xFFFFFFFE indicating the request was not valid for a number of reasons. This was observed sending the empty string, sending characters disallowed in a game name, and sending a string of a game that did not exist. In no case did this cause me to be IP-banned. There appears to be no differentiation between passworded and public games.

The field unknown appears to be the level restriction. It should be interpreted as 2 bytes not one word. The first byte read off the wire is the level to start from. On game creation this appears to be the creator's level but it can change as the creator gains levels or leaves the game. The second byte should be interpreted as the level difference. e.g. creating a game with a level 98 character with level restriction set to 30 results in 0x62 0x1E initially (again, this can change). To find the level restriction displayed in-game take the range to be max(1, level-difference) to min(99, level+difference). Thus a difference of 30 for a 98 character reads as 68 to 99 in-game. If there is no restriction specified these fields are both zero.

There is no restriction on requesting game information. A character need not be of the correct type, have the game password, have completed the correct difficulty, nor meet the level restriction in order to request game information.

Caaaaarrrrlll

Hi Kaylin, I've imported your email as a comment.

Thanks!

Kaylin

byte unused is actually string game_desc. You'll get the empty string if empty. In addition the terminating message that terminates the gamelist seems to be an additional byte in length, I'm not sure if it's always an additional byte in length. In retrospect this should have been obvious to me as the client gets the game description from this message too.