Launch Diablo III Bypassing the Launcher.

Most people do not need and should not bypass the launcher. But some people do, so...

 
Windows
Launch using a shortcut.
 
  1. Create a shortcut to Diablo III.exe
    (The default one points to Diablo III Launcher.exe)
    • Go to your Diablo III folder, Right click on the Diablo III.exe file, then click on Copy, now click in a blank space within the folder and "Paste SHORTCUT". (You can move the shortcut to your desktop)
  2. Right click on the new Shortcut -> Properties.
  3. On the Shortcut tab, add -launch at the end of the Target field.
    "C:\Program Files (x86)\Diablo III\Diablo III.exe" -launch
  4. Now launch the game using the newly created shortcut.
 
Mac OS X
Launch from terminal or create a shell script
 

To do the same on a Mac, you need to create a shell script and pass the -launch argument.

https://us.battle.net/d3/en/forum/topic/4927104190#20

Posted by Cleau.

Open Terminal and type:
open "/Applications/Diablo III/Diablo III.app" --args -launch

-or-

Open the AppleScript Editor and enter:

tell application "Terminal"
	do script "open \"/Applications/Diablo III/Diablo III.app\" --args -launch"
end tell

Then save as an application for easy double-clicking (or adding to your dock).
 
Errors
Things that might go wrong.
 

Streaming initialization error:
Whatever was preventing the Launcher from working is probably doing the same to the game. Deleting the Diablo III.mfil will disable the in-game streaming and should allow you to launch the game, but you MUST have the MPQ files 100% downloaded and if something is corrupt, the game is going to crash. (Removing the streaming server which is causing trouble may also work)

Unable to validate core data files error:
1, You haven't finished downloading the game.
2, You patched the game manually and now you're missing one or more MPQ files.
3, Something is corrupt.