Think back to the old cliches of unwashed teenaged boys playing DnD in their basement with vague costumes. This was back in the days where DnD was still complicated and confusing enough to feel like an exclusive club.
Back when THACO was the order of the day and you couldn't play monsters.
This, ladies and gents, is exactly what they would have been playing. ADnD has survived to this day as a game people play, despite three editions afterward-an honor which First ed and third ed never achieved. It's got a different feel to it,