RPGMemes

The whole We play a game so you have to cooperate together even if role-play wise it makes no sense is a bad practice, May-be not at the point you'll leave the table but definitely a serious sign that the table doesn't function properly.

Luckily, there is a very easy fix Do a session zero, and build a coherent party ab initio, it include in game reason for the party to work together, coherent goals (because when player A wants to abolish the reign of the emperor, and player B wants to defend the emperor you'll have a PvP fight within 3 session) and a meta discussion to have a pallet of skills matching the party's goal (At least in more epic game where you don't want to feel powerless). Almost every RPG published in the last 10-15 years contains an extensive session zero guide and tons of tips to build a relevant party.

If someone wants to play a law priest in a pirate campaign or any other character not fitting the campaign theme or opposing other PCs, it's perfectly OK to tell the no. Obviously if everybody is aligned on some PvP and betrayal the answer may be different, but it's again something to address in session zero.

Generally speaking, this is something that an experienced GM can handle in session zero. An important part of session zero is establishing expectations for the style of game to be played: Things like "are the player characters friends?" "Is PvP encouraged or discouraged?" "Do I as a DM want the characters to stick together?" etc etc.

Generally when running DnD, I request of my players to design characters who:

1. Have a disposition to get along well with their companions. (this can be for any reason: because they're like that with everyone, or because they're loyal to the group, or because they view it as useful to have some friendly scapegoats nearby or any other motivation.)
2. Be the kind of person who will go on adventures and take risks. (This can be because they're a daredevil, or because they're desperate, or because they're devoted to their duty, or any other motivation.)

Fundamentally, most DnD games are the story of a group of friends going on adventures together. If your DnD game is the story of a group of friends going on adventures, then it's extremely beneficial for your players to build characters who will be friends, and who will go on adventures. Together.

Compleatly understandable. Roll three d20... unfortunelty, your character died from sevear case of buzz kill. Go ahead an roll out n new one that is exactly like this one but more trusty toward people exactly like those in the party.