Although it possible to download RLCraft as a package from forge servers this installation method is rather complicated. As such most people choose one of two alternative services for launching the modpack that are both rather easy.
Twitch and Technic are both alternative launchers. Once you download and install either simply search for the modpack, install it and hit the play button. It is however highly recommended to use the Twitch launcher, as it causes far less issues and is much easier to work with. It will also allocate the right amount of RAM required for the modpack right off the bat, which Technic will not do. Generally speaking, Technic should only be used by those already experienced with it.
When you click play, the Minecraft launcher will show up. After this, you can hit play. After hitting play, Minecraft will boot up. Be patient, as this is a modpack, which means it will take longer to boot up.
Here's a video on how to download RLCraft on the Twitch Launcher.
Manual Installation (Windows)
Step by step instructions on how to install manually RLCraft. This method works with the original minecraft launcher and should also work with other launchers, but depending on which one you use the steps may vary.
- Download forge-1.12.2-22.214.171.12438-universal.jar from here
- Install forge (select install client)
- Download RLCraft Server Pack from CurseForge
- Go to %appdata% folder
- Create a new folder in it and rename it to rlcraft
- Extract server pack archive to rlcraft folder
- Run minecraft launcher
- Navigate to installations and create new one
- Name it RLCraft
- Set version to 1.12.2-forge1.12.2-126.96.36.19938
- Change game directory from .minecraft to rlcraft
- Allocate more ram (4 GB is what is recommended, going above can cause issues with memory leaks due to how Java itself works.) by clicking more options and changing JVM argument (-Xmx2G to -Xmx4G ; G represents gigabytes and the number how many)
- Click create.