Disclaimer: By attempting any of the processes listed in this thread you accept full responsibility for your actions. I will not be held responsible if your device stops working, catches fire, or turns into a hipster and claims to have been modified before it was cool.
Warning: Rooting does not void the OnePlus X’s warranty, though damaging your hardware (i.e., burning up your CPU/Motherboard by overclocking, hardbricking the device) will. You proceed at your own risk! I accept no responsibility for what you do with your phone. Follow the directions closely, and the odds are you will succeed without any trouble. If you are not sure what you are doing, do some more research before you try.
Lets begin 
Index:
1. Drivers Installation (Oneplus X, Fastboot & ADB)
2. Unlock Your Oneplus X Bootloader
3. Install & Boot into Custom Recovery (TWRP) on your OnePlus X
4. Make A Nandroid Backup With TWRP Recovery
5. Root Your Stock Rom
6. Backup EFS and Other Partitions
7. Install A ROM with TWRP Recovery
8. Install A Custom Kernel With TWRP Recovery
1. Drivers Installation:
In order to Root or Install Custom Recovery on your Oneplus X, you need to have the right set of Drivers to help your computer recognize your device. I used Windows 7 for this and it worked fine so should work for other windows as well.
Download OnePlus USB Drivers and install.
Go through the setup, and when done, restart your PC. Connect your OnePlus X to your windows and is shall recognize it 
Set Up Fastboot & ADB Drivers:
What’s ADB?
ADB stands for Android Debug Bridge. It works when the device is powered on and booted into OS or Recovery. The tool helps in sending basic linux commands, and a variety Android specific commands from PC to connected Android devices.
What’s Fastboot?
Fastboot works only in bootloader/fastboot mode. It allows you to re-flash system partitions on your Android device and requires a device with an unlocked bootloader. It’s particularly useful when you want to update your device manually or in a rare situation when you accidentally soft-brick your device and need to install a clean stock system image.
Thanks to XDA member Snoop05 who has developed a small program to quickly install both ADB and Fastboot files on your PC (system-wide) along with proper drivers.
Downloads and installation instructions below:
Setup ADB & Fastboot in 15 Seconds
Download 15 seconds ADB Installer (Disable your Anti-Virus on the System)
Filename: adb-setup-1.3.exe
1. Download theadb-setup-1.3.exefile from the download link above.
2. Double-click/Run theadb-setup-1.3.exefile.
3. You will see a command prompt window with blue background. Say YES to all the prompts on this screen.
└ To say YES, just type Y and hit enter.
Once ADB, Fastboot and Drivers are installed, the setup window will automatically close and you’ll have a working ADB and Fastboot setup throughout your system.
2. Unlock OPX Bootloader:
Backup important files stored on your OnePlus X before proceeding with the steps below, as unlocking the OnePlus X Bootloader will completely wipe/delete all files on the device.
After the installation of drivers (OnePlus X, Fastboot & ADB drivers) follow the below to proceed with Unlocking the Bootloader of your Oneplus X
Enable USB Debugging & Activate OEM Unlock:
* Go to Settings > About phone, and then tap ‘Build number’ 7 times or until you get the message ‘You’re now a developer!’.
* Go back to Settings, choose ‘Developer options’. Find the ‘USB debugging’ option and use this toggle button to enable it. Accept warning by tapping on OK button.
Also in the ‘Developer options’. Find the ‘OEM Unlocking’ option and use its toggle button to enable it. It asks for your PIN/Screen unlock code, type it. Then accept the warning by tapping on OK button.
Connect your OnePlus X to windows now. You will get a pop-up as shown below on your phone when you connect for the first time after enabling USB debugging. Select ‘Always allow from this computer’ checkbox and then tap on OK button. (You may or may not get this prompt so don’t bother if you dont)
Boot your OnePlus X into Bootloader/Fastboot mode. (Make sure you have backed up all important data as you’ll lose everything on phone in the steps below.)
Connect your OnePlus X — in Bootloader mode — to PC. Let the driver install.
Open a command window on your PC. For this:
Open any folder on PC. Now, left click on empty white space inside the folder.
Hold shift key, right click on empty white space to get a pop-up as shown below.
Choose Open command window here option from that.
You will see a command window open up, with location directed to unlock folder.
Power off your phone then boot into fastboot mode (power + volume up).
Connect your phone to your windows via usb cable.
Confirm whether fastboot is working. With OnePlus X connected to PC, run the following command in command window.
Code:
fastboot devices
It should return your device serial number, if not you need to make sure your drivers are installed correctly.
Once you've confirmed your fastboot connection to unlock the bootloader use
Code:
fastboot oem unlock
The device will now go through the automated unlocking process, just let it do its thing and it'll boot up into Android.
You’ll see a new screen on your device. Choose Yes and confirm it.
That’s it. The device will reboot automatically.
To confirm unlock status, reboot into bootloader/fastboot mode and you shall see the text unlocked now.
Code:
fastboot oem device-info
It should have a couple of lines there, both with the flag set to true.
PS: Some users have reported the process to work even on false device tampered status, so ignore & continue if u are one of them.
3. Install a Custom Recovery (TWRP) On your OPX
Modified Custom TWRP Recommend Download
PS: Don’t try this on any other device whatsoever except the X.
>Enable USB debugging from developer options once again.
>Download the Custom TWRP recovery file from above.
>On PC, rename the TWRP file to recovery.img
>Boot your OnePlus X into bootloader mode.
>Connect your OnePlus X — in bootloader mode — to PC. Let the driver install.
Open a command window on your PC in the folder where you have the recovery.img file.
You will see a command window open up, with location directed to folder where you have the recovery.img file.
Let’s confirm whether fastboot is working. With OnePlus X connected to PC, run the following command in command window. You should get a serial no. with fastboot written after it. If not, you need to reinstall the fastboot drivers from above.
fastboot devices
> Flash TWRP recoveryon your OnePlus X by running the following command.
fastboot flash recovery recovery.img
> Boot TWRP recovery on your OnePlus X now by entering the following:
fastboot boot recovery.img
Or you can manually boot in recovery by unplugging the usb cable and then pressin POWER + VOL down until the device boots. When the Oneplus logo shows up, relese the POWER and keep holding down VOL DOWN until TWRP boots.
Don't boot the OS on the phone as it will overwrite the recovery
4. Make a Nandroid Backup With TWRP Recovery
Nandroid backup is a very important thing to have before installing any custom software on your device. It's basically a backup of your stock system that you can fall back on if anything goes wrong or if you just want your stock ROM back. You can also use the backup tool to create a backup of your favourite ROM set up exactly the way you like it. The backup you create can be easily restored using the restore tool in TWRP recovery.
All you need to do is enter TWRP recovery, select the backup option from the TWRP home screen, check the system/data/boot boxes, and swipe to backup. The process will take a few minutes.
Please make this backup before you root, so that you possess unrooted system backup at all times which would come handy at the time of OTA updates.
5. How To Root Your Stock Rom:
Download: SuperSU on your device.
Reboot to recovery
Tap on Install > Browse and Select SuperSU > Swipe to Confirm the Flash
Once Done > Wipe Dalvik & Cache > Reboot System To Restart
To Confirm the root status use a root checker app from play.
Now you possess an Unlocked OPX with a Custom Recovery and Root Privileges
Cheers,
Funk Wizard
Last edited: Nov 18, 2016
Its still in mandarin or something. What do i do? Is this got something to do with the phone? or the recovery image itself?
Last edited by a moderator: Nov 8, 2015