Things You'll Need
Instructions
Install the G.E.C.K. software, by double-clicking the ".exe" file downloaded from the Bethesda Softworks' website. Click "Next" until the installation completes. Then open the G.E.C.K. software by double-clicking the shortcut made for you during the installation process.
Select the small check box next to "RR Companion's Vault.esm" and click "OK." A warning will pop up: "You have not selected an active file." Click "Continue."
Select "NPC" from the left-hand side of the "Object Window." At the top of the window is a small white box labeled "Filter." Type "v1" into the "Filter" box. On the right side of the window, a list of names appears -- beginning with "v1." Double-click on any of these names.
Name your companion by filling in the "Name" box of the "NPC" window that appeared. After you're finished, type the same name into the "ID" box above, and make sure that the "ID" box reads "v1(your chosen name)." For example, if you name your companion "Steven," the "ID" box reads "v1Steven."
Look at the center of the "NPC" window. There are a number of drop-down menus to help customize your new companion. You can select any "Race," "Voice Type," "Class" or "Combat Style" you want. Feel free to experiment with all the options available.
Select the "Face" tab from the top of the "NPC" window. You may have to scroll to the left or right, using the small arrows located in the right corner of the window. In this tab, you can select the "Age," "Complexion" and "Hair Color" by manipulating the sliders and text boxes.
Select the "Face Advanced" tab at the top of the "NPC" window. Use the large list of options given and the slider on the left, to create the face of your new companion. When you've got the exact look you want him or her to have, click the "OK" button. Then click "Yes," when the small window pops up asking you to create a new value.
Select any location from the "Cell View" window on the right side of the editor. This lists every location in the game, so find one you remember and double-click it. Once it's loaded, you'll be able to see it in the "Render Window" above.
Drag and drop your new companion from the "Object Window" on the left, to the "Render Window" on the right. This will place your companion within that location in the game. Click "File" at the top of the window, and select "Save." Name the file something you'll remember, and press "OK."
Start "Fallout 3" by double-clicking its icon on your desktop. Select "Data Files" from the menu, and you'll see the name of the file you just saved. Click the small check box next to it, press "OK" and start the game. Once you reach the location you placed your new companion, you'll find him or her waiting for you.