Until now, joining meant bringing your own copy of the game on 3.3.5a and editing the realmlist by hand. That still works—and it is still a single line of text—but on Windows it is no longer the only way.
- It downloads the complete 3.3.5a game client.
- It checks every file against its SHA-256 hash before accepting it: anything that arrives truncated or corrupt is downloaded again.
- It leaves the realmlist already configured, so there is no file left to edit.
- The game opens with Frosthold.exe.
It is around 17 GB, so leave plenty of free space and do not be in a hurry. Checking happens file by file: if something breaks later, only that piece is downloaded again, not the whole 17 GB.
A note for anyone doing it by hand: the realmlist file lives inside the client language folder, not in the game root. The client the launcher installs is in Mexican Spanish, so there the folder is esMX; if you bring an English client, it will be enUS.
macOS and Linux, by hand
There is no launcher for macOS or Linux yet. On those systems setup is the same as always: your own 3.3.5a copy and one line in the realmlist. How to join explains it step by step.