Tabletop only. No kids, pets, drugs, or cell phones.
Beer is fine, but if you “fall asleep” your character is then under the control of whoever wants a mobile hit-point sponge/mule that game.
Sadly, in college, I once had to also make a “no pr0n at the table either!” rule. But we don’t game with that guy anymore, so it hasn’t been a problem since.
I’ve got several other rules, all written down (mostly common sense stuff.) Tabletop clearly has its problems... But I wouldn’t want to game any other way!