Honestly, this is for me all linked to the level of self-centricity of the player. When you have players who come to the table so that their friends enjoy the game, you have fantastic players and great games. When you have players who come to mostly enjoy themselves, with often less or no regard for the other players at the table, it quickly becomes much more complicated.
As a link back to the other threads, this is also why I consider that it's a fault that I encounter much less in DMs who, by default, come to have players play in their campaign, so who, by default, centre their play around others. It does not mean that there are no adversarial DMs (I've never met one who was truly that way, and apparently some can be good for some type of games although my preferences run in other directions), but that for me it's harder to be all about "me! me! me!" when you are not really playing yourself (but it might mean that really bad DMs are probably those who play for themselves ?).
This form of selfishness on the table can take many forms, whether it's technical or in terms of role or general attitude, but for me it's the root of the problem. Whether it's ruining the game for others, ruleslawyering to show one's knowledge of the rules, wanting to be stronger than others, wanting a specific role that makes other reacts, often negatively, it's all the same cause.
And Basically, it comes back to respect of the others, even before wanting the others to enjoy themselves. The session zero advice from Tasha is good about this:
- You will respect the players by running a game that is fun, fair, and tailored for them.
- The players will respect you and the effort it takes to create a fun game for everyone.
- The players will respect one another, listen to one another, support one another, and do their utmost to preserve the cohesion of the adventuring party.
- Should you or a player disrespect each other or violate the social contract in some other way, the group may dismiss that person from the table.
So, in the end, to judge the acceptability of a player for a table I'm at, it's certainly not about their knowledge of the rules, the build of the character, or the role that they want to play, it's all about whether they show the necessary respect for the other players.
And note that this does not prevent a character from being adversarial. We had an extremely long Runequest Campaign in which, as part of our Heroquests I was incarnating Arkat, the hero who joined cult after cult and betrayed them all one after the other in search of what was needed to destroy chaos, which meant that I was always the adversary and the betrayer in almost all heroquests that my friends undertook. But as it was done to further the game and provide them with the best adversary possible for them to shine, it resulted in a great campaign. Characters may be strongly adversarial, but as long as the players are not, it's not a problem.
After that, again, for tables who are there about the technical challenge and "playing against the DM to overcome the difficult challenges", the "adversarial player" might be an asset, but it's so opposite to my personal preferences of playing the game as totally collaborative that I cannot comment.