This is taken from this Beamdog blog post as an archive in case it disappears: http://blog.beamdog.com/2018/12/how-to-install-custom-content-to.html
Transferring to your Device
In order to install custom content to Neverwinter Nights: Enhanced Edition on Android, you will need a way to add files onto the Android file system. We suggest you use a desktop computer and a USB connector cable (data cable).
In order to view your Android device’s file system from your desktop device, please see the following Google Support Page: https://support.google.com/android/answer/9064445
On your desktop browser, open the Android Device as a remote drive, and navigate to the following folder:
Android > data > com.beamdog.nwnandroid > files > user
NOTE: There is also a “data” directory. This is used by the game to store base game data. Patches will overwrite or delete your modifications. Make sure to only modify the “user” directory.
If the device does not show any content, please ensure that you have chosen to “Allow access to phone data” when prompted on the phone.
Custom content downloaded to your desktop can be installed to Neverwinter Nights: Enhanced Edition on Android by dropping files into the appropriate sub-folder:
- Modules should be installed to the modules folder (.mod files)
- Hak packs should be installed to the hak folder (.hak files)
- Talk tables should be installed to the tlk folder (.tlk files)
- Override packs should be installed to the override folder (loose files)
- Custom portraits should be installed to the portraits folder (.tga or .dds files usually)
The directory layout in user mirrors what the Desktop version of the game uses. If any of the above folders do not exist, they can be created and placed into the user folder.
In order to import a save file, navigate to the following folder:
Android > data > com.beamdog.nwnandroid > files > user > saves
Save games can be dropped into this folder, and can also be copied from this folder into the desktop version of the game.
For hundreds of community created modules and more, check out neverwintervault.org, a fantastic Neverwinter Nights community of content creators.