In pen & paper roleplaying games nowadays there is frequently a "session zero", in which the social contract of playing the game together is discussed. That avoids conflicts later, when some people in the group wanted to play one way, and others in a very different manner. It allows you to discuss what sort of behavior is acceptable, and what not. But for board games I have never heard of anybody doing something similar.

My wife and me don't like to play competitively against each other, so I mostly buy cooperative or solo board games. But even there we don't necessarily have exactly the same motivation: My wife is mostly playing for the experience of playing, while I can't always switch off my "gamer genes" and also try to play well. I like to understand complex games well enough to be able to play them competently, to understand the underlying gameplay mechanics. For example I wrote a blog post over a year ago on how to win at The 7th Continent; and sometimes I see YouTube videos of people playing the game, not understanding how it works, and then giving it bad review marks for being too hard. I find that somewhat annoying.

But then it is surprisingly hard to find good sources on board game strategy. I recently started to play the digital version of Wingspan, which is excellent, but didn't have much luck finding good advice on how to play the game better. When you search about strategy advice for Wingspan, you will find lots of discussions on which individual birds are overpowered, but as you don't necessarily find one of these overpowered birds in your starting hand, that advice isn't all that helpful. After a number of games I understand the mechanics of the game well enough to get to over 90 points, but I haven't breached the 100 point barrier yet. But then, 90 points seems to be the "competent player level" of the game, I've seen the designer play Wingspan on YouTube and get 93 points. I can see how Wingspan would be fun to play as a board game with a group of people all playing at that "competent player level". But I could also see a group of friends or random stranger sit together and them having very different level of competence and experience with this particular game, and that then not being much fun at all. Wingspan is an "engine building" game, and if one player builds a far inferior engine than the others, his turns will be much shorter, give much less resources, and feel much less fun.

It is easy to see that players will often have different levels of experience with a competitive board game, and possibly different motivations. If one player not only knows the game much better than the others, but also has a competitive motivation to crush his opponents, chances is that nobody will have much fun in the end. Cooperative games and pen & paper roleplaying games are a much safer ground. But maybe talking about the social contract before starting to play would be a good idea too.