[Moto Z2 Force  Guides, News, & Discussion] Uzephi:
Since no guide has been updated with information on official TWRP for root and backup reasons, I thought I'd create one.

DISCLAIMER:

To do this method requires you to unlock your bootloader. Your warranty is now void. This method assumes you have basic knowledge of ADB and Fastboot commands and know how to recover your device if you accidentally type a wrong command and now boot to TWRP and can't boot to system. If you cannot recover from this, Read up on guides to "return to stock" and familiarize yourself on how to recover your device should something go wrong.

There are two methods for root. You can flash TWRP to your boot image to be able to reboot to TWRP without a PC, or just a temp boot so you can just have root and not TWRP. I'll put in brackets the minor differences.

1: Get ready

Download latest build of TWRP img file from their website.(Previous link is to their instructions and device specific patches, download page is HERE.) {download the latest zip if you want to flash TWRP}

Download what you want on your phone (SU, Magisk, etc)

2:

Hook phone up to your PC, be sure you have latest adb/fastboot drivers. (I do not support windows related questions. If you have latest drivers, you'll have no issue with the below commands, Linux just works for this kind of thing)

3:

Navigate to your directory that has that img downloaded. (windows, shift right click and say "open command prompt here")

Type the below commands, and terminal output should be similar: (I.E. this is a copy/paste of terminal)

Main thing to remember is "Fastboot boot {filename}.img"

uzephi@Nash:~$ adb reboot bootloader
uzephi@Nash:~$ cd Downloads
uzephi@Nash:~/Downloads$ fastboot boot twrp-3.2.1-1-nash.img
downloading 'boot.img'...
OKAY [ 0.841s]
booting...
OKAY [ 5.135s]
finished. total time: 5.976s
uzephi@Nash:~/Downloads$

BE SURE TO DO BOOT AND NOT FLASH!!!

(If you ask why you can no longer boot to system, I'll let you know you missed this line.)

5:

You're now in TWRP!

It will ask you for your password. This is your PIN or password to unlock your phone. Enter it.

TWRP has now decrypted your storage to read the zip file(s) you put on your phone!

Go to install and navigate to your directory where you put that file

Install Magisk/SU/TWRP/whatever you please.

(Note: some root zips require a factory reset)

6:

Reboot!

You're Done congratulations!

Attached are images if they help you see you're doing the right thing.

Special thanks @erfanoabdi @invisiblek @npjohnson @joemossjr @jbats

Without the above people a lot of what's above woudn't have been possible for this device specifically. Also, thanks to everyone who pitched in to get a device over to invisiblek. Leaps and bounds have been done since that donation. And thanks to the other devs who have invested in this phone and their time to help out.

(Quoted from Nathan Chance)

Quite a few people have asked to donate to me in the past and I have turned them down. I am not in this for the money, this is my hobby, something I truly enjoy. If you truly want to donate to something (it is not expected in the slightest), I recommend an entity like the Open Source Initiative, the Free Software Foundation, XDA, or any one of the people I have thanked in the OP. Additionally, you are free to copy any and all of my work; the only thing I request is that you not ask for donations as well (though I can't really enforce this lol). Thank you.