You can do the pub with two, sure, but even the closest of companions will find lulls in the conversation.
No, three is the ideal – keeping the chat at a constant simmer, taking it in turns to interrogate or listen, and nobody left alone while the round’s got in. And three will fit anywhere, from the tiny round table in the tiny snug, to the end of a bench, to leaning on the bar.
Four and five work too, though the balance is never quite as good as with three. It’s too easy to end up in a row, player one unable to hear player four, player five cast adrift and in everyone else’s way on a stool dragged across to the end of the table.
Six? You need a biggish pub with plenty of room to pull off six, but it can be done on special occasions: you can’t see A without telling B you’re coming out, and B will want to bring C, and if C’s there it would be rude not to invite D… But the conversation either fragments, or ends up with everyone yelling over each other. You’ve to work hard in a six.
Eight is just daft. Avoid eight. That’s a dinner party, that is, or a committee meeting. Coats in a pile, not enough chairs, “You swap with her so she can talk to him about them”, tables dragged together and bar staff rolling their eyes. Except in the biggest of booze barns your group of eight is a dominating and probably irritating presence.
Then there’s twelve… Are these people barmy? Five tables in a row down the middle of the room so nobody else can get to the bar or toilet or the smoking lean-to. High chairs and pushchairs. A camera on a tripod. Is somebody making a speech? “Let’s pile the presents on this table here to get them out of the way while we eat.”
Even better, the central London speciality: fifteen, with no booking, guidebooks in hand. Shuffle in, shuffle all the way round looking for the magic unreserved banqueting table, then shuffle out again looking sad.
No, three is the ideal size for a team in a game of pub.
Though there’s also a case to be made for one.