From Droidviews: http://www.droidviews.com/root-motox...ith-superboot/
A Moto X 2014 with unlocked bootloader. You can unlock the bootloader by following the instructions given at Motorola official page.
Set up ADB and Fastboot on your computer or download the minimal ADB and fastboot tool from here (unzip it).
Install Motorola USB Drivers on your computer.
Download the modified boot image by jcase: pure2014sb.zip
Open Settings> Developer options and enable USB Debugging on your device.
Root MotoX 2014 Pure Edition with Superboot
Having taken care of the prerequisites mentioned above, you can now proceed to root your Moto X 2014. Just follow the steps given below.
1. Extract the pure2014sb.zip file and copy the pure2014sb.img file into the platform-tools folder (in case you have Android SDK installed) or copy the files into the mfastboot v2 folder.
2. While the folder with ADB and fastboot files is open, right-click on an empty space and select “Open command window here” option to launch a cmd.
3. Connect your Moto X 2014 to computer using a USB cable.
4. Now type the following command in the cmd window and press the Enter key:
adb reboot bootloader
5. Your phone will reboot into the Fastboot mode.
6. Then issue the following command:
fastboot boot pure2014sb.img
7. When the phone boots up, install su and quickly reboot it.
8. When the device boots up again, go to Google Play store and install the SuperUser app.