Guide to bypass Rockstar Launcher
I recently wanted to play GTA V and Read Dead Redemption 2 offline, but I couldn't. In theory, you can play offline for 7 days after playing the game online, but in practice, it almost never works. So I bypassed it.
Step 1: Download Nightlight Game Launcher from GitHub. I've heard people say it contains malware, I didn't have any issues and I know that license spoofing programs can be misidentifying as malware at times, but be careful.
Step 2: Add it to Steam. Right click the .exe and add it to Steam.
Step 3: Open your game's directory. Be it the GTA V or RDR2 directory, open it by right clicking the game and Browsing the Game's Files under the Manage tab.
Step 4: Create a Link to the Desktop. Copy the game folders location by right clicking it and selecting copy location, then create a new link to the folder on your desktop and enter the game's path.
Step 5: Get back to the .exe you added to Steam, right click it and run it with Proton Experimental as a compatibility tool.
Step 6: In the program, select your game and specify the location. Use the link on your desktop to do that. Now click "install modules" and wait.
Step 7: For GTA V, add
-nobattleye
as a launch command. For RDR2, add
cmd=( %command% ); cmd[-1]="$STEAM_COMPAT_INSTALL_PATH/Launcher.exe"; "${cmd[@]}"
as the launch command. This will make sure that the game won't try to run the Rockstar launcher but use the fake one instead.
You're good to go now! If you start the game, you will start from the beginning. Don't worry though, your save data isn't lost. Start the game and play for like a minute to make sure the necessary files are created. Now, go to your compatdata directory (you can find it on the PCGamingWiki) and navigate to users/steamuser/Documents/Rockstar Games/. Now open your game's folder, navigate to profile and copy the contents of the folder with random letters as a name.
Go back a few directories until you're at users/steamuser/ again. Open the App data folder (It might be hidden, make sure to enable the "view hidden folders" option). Now open the Local folder. There should be a folder here named either some random numbers or something more logical like LauncherBypass or something along the lines of that. Just open all the folders and see if you find a Profile folder inside. If you do, paste the stuff you copied earlier. If you get asked if you want to Overwrite the existing items, choose skip for all items.
Now launching your game should skip the Rockstar Launcher and throw you right into the game, enabling always offline play. I have no idea how to uninstall this mod and it disables Online play functionality (though GTA Online doesn't work anymore anyways, sadly). This method should also work for GTA IV, but I haven't tried it yet. Also, as I said in the beginning, the program got flagged as malware by multiple anti virus softwares, so be careful.