Proposals / #1105

Name the 0x57 sender's mod and champion parameters from what the client does with them

checked · by dtchitt · submitted 2026-11-03

NET_D2GS_SERVER_Send_0x57_CHANGEMONSTERUNIT's wParam1..3 fill packet bytes 8, 0xa and 0xc. Its one caller, MONSTER_SendNpcEnchantsToClient (call at 00597cd9), passes the first two bytes of the monster's umod list as one word, the third umod byte, and CheckMonsterType(pUnit, 4), the champion bit. The client handler NET_D2GS_CLIENT_Incoming0x57_CHANGEMONSTERUNIT (0045e400) writes word 8 back as umods 0 and 1 and byte 0xa as umod 2 of GetMonUModList, and sets monster type 4 (champion) when word 0xc is non-zero. Live in d2-re: after each Summoner's S2C 0xac the server sent 0x57 with [5] 1, the name seed at 6, the umods at 8 and 0xa, and the champion word at 0xc. Hence wUMods01, wUMod2 and wIsChampion.

Changes 3, applied together

1. Rename variable win 0x0053d880 Stack[0xc]

   namewParam1→wUMods01

2. Rename variable win 0x0053d880 Stack[0x10]

   namewParam2→wUMod2

3. Rename variable win 0x0053d880 Stack[0x14]

   namewParam3→wIsChampion