All of that started with a mod for Quake 2 called Action Quake. You could break your legs by falling or bleed out, and had to bandage, that kind of thing. It was the predecessor to Counter Strike, which in turn birthed a lot of modern shooter mechanics.
I used to play Action Quake 2 for years pretty seriously. Looking at the gameplay videos of it now it looks so much like a pre-pre-alpha version of CS:GO still to this day.
