HTC Desire 820 ROOT tip

HTC Desire 820 can be easily rooted with few simple steps.

I am not responsible for your warranty loss or device not functioning properly.

Steps
1] Unlock Bootloader if you don't know how to do it visit this page
2] Download TWRP Recovery from here 
3] Download Super Su from Here and transfer it to your device
4] Reboot to Fastbboot mode using Volume Down and Power Key
5] Connect Phone to PC
6] Extract files from Recovery.zip in one location and simply click on flash-recovery.bat
7] After Step 6 is finished Using volume keys navigate and select recovery option and go to recovery
8] After rebooting in recovery select Install zip > and selecting supersu.zip transferred in first step to obtain root access.
9] Reboot


Source