That's the important line right there. Not hard if you're gaming with people you know and trust, but when it comes to completely random parties put together -- such as PUGs or, in tabletop terms, convention tables -- it's often not even worth bothering to risk it, because you never know who you're gonna end up sitting with.
I'm sure as heck not going to spend hundreds of dollars traveling to a convention just to hear some socially-inept goofball with only a vague understanding of his character and a folder at home containing fancfics he wrote of every other player's characters in his home game sit there with a confused look on his face and complain to the rest of the party why they aren't helping or at least recovering his corpse after he willingly and knowingly walked through a still-present blade barrier twice.
And why no, I'm not making that story up for the sake of hyperbole. I wish I was tho.
