here is How to root lg G3 verizon and AT&T and the International versions of the Lg G3….
The Things you need to proceed :
2.Latest ioroot tool : [download here ]
3.Lg G3 !!!!
1.Download and extract the latest ioroot.zip… datroot.zip is inside /ioroot/bts/
2.Enable “USB Debugging” on phone. Accept RSA certificate to allow ADB access. Not accepting RSA will cause ADB device to show as “offline”
Verizon users must also enable “Ethernet” for USB mode.
3.Run ioroot.bat, ioroot.sh, ioroot.tool or open command prompt/terminal, cd into /ioroot/bts/ and type
” adb reboot recovery “
Double-click on ioroot.bat
Open terminal and cd into ioroot folder
chmod +x ioroot.sh
Double-click the ioroot.tool file to launch script.
May need to chmod +x ioroot.tool file first. }
4.Now Select “Apply update from ADB” w/power button. Sideload mode is now enabled.
5.Continue with the script and type
" adb sideload datroot.zip "
Congrat’s your Lg G3 is now rooted and you can now install ” supersu ” from play store and can check the root with root checker app from play store.
If you are stuck with any of the above steps then follow this video :