Only rule I can think of during our Intellivision days was our parents got to play as long as they wanted first and when they were ready for a break, I got a shot. My Brother played less because he was pretty young during most of that period and the 8-bit gen was his equivalent. My parents weren't interested in video games after Intellivision.
Holy shit, my story is eerily similar, except I was the younger brother (but I played more than my older brother, which means you are not my brother).
My parents were absolutely hooked on Burger Time and Lock n Chase, which they bought for $1 each at, I believe, Kmart, during the great video game crash. I remember my dad had a shopping cart almost filled to the top with Intellivision games, a new console (to replace the old one with the shot controllers) and the Intellivoice ("Mattel Electronics presents - SPACE SPARTANS!!").
Once we got older, there were no real restrictions for the Master System and later, Genesis. We all had really good grades, did a lot of extra curricular activities, active in sports, etc., so there was no need for rules.