Several years ago, I met this guy at work who gamed. He invited me and one of my players to his game to play. So we showed up with two very evil characters (a cleric and an anti-paladin) both dressed in classic EVIL GEAR.
Well, the players in this other group were serious ROLL players, but not at all concerned with ROLE palying. So when our characters met theirs, they never bothered to ask what we looked like, or acted like or anything. Even the DM, who saw our character sheets, never bothered to tell the players what we looked like.
So we went around killing things with them for a few hours, then, as the session got near the end, we decided we had had enough of the goody-goody paladin who was leading thier group, so we tricked the rest of the party to go off into this other room for a minute, and we attacked the paladin.
They were all shocked.
"Are you evil?" they asked.
"Hell yeah!" we said. "I'm dressed in black, I got a big skull on my helm. I have a big unholy symbol on my chest and everything!"
"I didn't know that." the paladin's player said.
"you never asked what we looked like." we said. "you never even asked our names. We just started going around killing things together."
So we never played with them again.