Install and connect

From nothing to the character-select screen in four steps.

Register. Create an account on the Register page. Use a real email address you can reach; keep your password private. Staff never ask for it.
Download. Get the launcher from the Download page and run it. It installs the client and downloads every patch, so there is nothing to merge by hand.
Let it patch. The first run downloads the full client and can take a while. Do not close the launcher until it says it is ready.
Log in. Start the game from the launcher, enter your account name and password, pick a server and create your character.

Problems

Windows or antivirus blocks the launcher: the game files are modified, so some antivirus tools flag them. Add the game folder as an exclusion if you trust your download from this site only.
Cannot connect: check the server status. If the server is online, see the FAQ.