[Nextbit Robin] Raiz:
This method is deprecated, the first steps still work but the magisk part isn't recommended anymore, I'll update when i'll have some time

Root acces is to be allowed to access the Android system files. In UNIX-based systems like macOS and linux you can have root access (system file access) with admin password, it's different for Android tho...

In Android, Google doesn't let the root access opened for the main user of the smartphone, it is closed for all. But they left us ways to gain the access ourselves (kinda).

To gain root you must:

1- Unlock your bootloader

2- "Boot" or "Flash" a custom recovery (like TWRP)

3- "Flash" the Magisk zip file.

Before you do anything I recommend you watch several videos of people doing the process before actually doing it (even if it's not the nextbit robin), because a lot of things can go wrong.

Disclamers:

**This process will wipe all of your data, please do a backup**

**It may harm your device too, be careful with it**

**You did it, not me, I'm not responsible for anything bad that could happen**

1-Unlock your bootloader:

a)Go to settings-->About Phone​

b)Press 7 time the Build number​

*developer options enabled*​

c)Go back (once) and go to "Developer Options"​

d)Enable ADB Debugging and OEM Unlock​

e)Plug your device to your PC​

f)Install the nextbit drivers if prompted (attached)​

g)Install adb and fastboot (follow the guide) then open the command prompt in the right folder (/plateform-tools) and get ready to start​

h)enter the commands: adb devices (see if your device appears) then adb reboot bootloader​

*device reboots to bootloader*​

i) enter the command fastboot devices (see if your device appears) then fastboot oem unlock​

*device wiped, bootloader unlocked*​

​

2-Flash or boot TWRP Recovery:

a)download the twrp img for our device (attached) (download here) and put it in a known folder (or in your plateform-tools folder)​

-->2 options here:​

->1st: Boot into TWRP (to use twrp once, does not install it):​

b)enter the command fastboot boot path/to/the/img/file​

->2nd: Install TWRP:​

b)enter the command fastboot -i 0x2c3f flash recovery path/to/the/img/file *recovery installed* then fastboot reboot recovery​

Tip: to easily have the "path/to/the/img/file", just drag and drop the twrp img file in the command prompt at the end of your command.​

​

3-Root your device:

You're in TWRP mode, you should see some icons

a)Click on the mount section​

b)Click on enable MTP at the bottom right of the screen.​

-->If the button says "Disable MTP", don't click (it's already enabled)​

c)Download the Magisk zip here on your pc​

d)Transfer it to your device through usb (enabling MTP on TWRP must have allowed your PC to see your device as mass storage on your computer)​

e)Go back to the main menu in twrp, and click the Install button​

f)Browse your phone's memory to where you put magisk zip​

g)Click on the zip file​

h)Slide to the right to flash (bottom arrow)​

i)Click on reboot​

​

After rebooting, there are some chances you get what we call bootloops (infinite boot animation). If you're not ready to put that at risk I don't recommend you to root, because that's a risky bet.

Also here's a youtube video on how to do it