Thanks to a video posted by Reddit user OkPain2022, we’re given a glimpse of how pickpocketing will work. Of course, you’ll still need to approach them by crouching, and after you do that, a prompt will appear, allowing you to steal from them. After that, another menu will appear, showing you what they have and the odds of you successfully stealing said items.
Fallout 1 already featured pickpocketing (that is, stealing from people the same way you steal from containers). Maybe that’s where they got the idea from.
They had pickpocketing in Arena; well before Fallout 1.