We finally now know how to perform root on the LG G3 and the best part is that it works on all variants including Sprint, Verizon, TMobile and AT&T versions.
Here is the method to root LG G3 and its Sprint, Verizon, TMobile and AT&T variants
* Install StumpRoot from here.
* Run StumpRoot
* Reboot after app tells you to
* Install SuperSU from play store market
* Uninstall StumpRoot
StumRoot is a brute force method of finding out when to attack in order to find the location where root can be performed. Here is a video to help you out.
Since this is a root exploit, it performs low level changes to your LG G3. Using the stump root method properly no data loss will occur.