I've always been certain that the name comes from the common children's game: https://en.wikipedia.org/wiki/Capture_the_flag https://en.wikipedia.org/wiki/Captu

I've always been certain that the name comes from the common children's game: https://en.wikipedia.org/wiki/Capture_the_flag https://en.wikipedia.org/wiki/Capture_the_flag right? The wiki article has a short discussion of how that morphed into video game terminology, which is the etymology that I'd expect without having researched it.