Table of Contents

Login & shard select

Seed, account auth, server list, shard select, game-server handoff.

Opcode Name Dir Size Description
0x80 Account Login Request C → S 62 bytes (fixed) Credentials for the login server.
0x82 Login Denied S → C 2 bytes (fixed) Rejects the login with a protocol reason code.
0x8C Connect To Game Server S → C 11 bytes (fixed) Redirects the client to the game port with an auth key.
0x91 Game Server Login C → S 65 bytes (fixed) The auth key from the redirect plus the account credentials.
0xA0 Select Server C → S 3 bytes (fixed) The shard index the client picked from the server list.
0xA8 Server List S → C Variable Advertises the available shards.
0xBD Client Version C → S Variable The client answers the server's version request with its build string (e.g.
0xEF Login Seed C → S 21 bytes (fixed) Connection seed and client version, sent first by ClassicUO.