RPGs are an unfortunately social pastime. I say unfortunately because a statistically significant number of humans have social difficulties which make them extremely incompatible with the significant number of humans who are made out of elbows. It would be a lot easier if you could get the same experience out of a cluster of artificial intelligences, but there is a reason person-to-person play persists as a hobby in an age of video games – the technology ain’t there yet.
Often this is just a matter of people having incompatible personalities. As in the example at the top, an introvert and an extrovert could be quite bad with each other. Political differences can spill into a game, with predictable results. Someone could have a punchy sense of humor while another is sensitive to insult.
Unfortunately, the person who is offended is more likely to leave a game than an offender. The offended could be someone who habitually deals with difficult people by walking away. Bystanders could be weighing the relative difficulties of an offended person leaving the game and confronting a belligerent person, and follow the path of least resistance. I say it’s unfortunate that the offended are more likely to leave because sensitive people are often great, and insensitive people are often horrible.
Sometimes this sort of conflict rises to the level of being a real mental health and disability access issue. What happens when the player with Asperger’s and OCD can’t help but aggravate the GM with Avoidant PD? The game is over for everyone. Sometimes there really is no solution to a problem.
To decrease personality conflicts, it can be helpful for all the players and GM to know each other well before a game begins. That’s where meatspace games usually have a clear advantage over online affairs. But there are just no guarantees. Say you know someone well, get on with them in all life circumstances fine. But when they RP, they act completely different in a way that makes the game unbearable for you. Unforeseen clashes like that have ruined friendships.
I actually have no solid advice on this issue. I only write about it to let anyone new to RPGs know an important reason why most attempts at a campaign fail. Forewarned is forearmed. Also, perhaps in the comments someone else will have something useful to say about it…