I'd just love this "D&D play - any edition char you want - TOGETHER" game.
Etc.
Just wait till BECMI joins the fray! The PCs might not even get out of the starting gate.
"What class are you?"
"An elf"
"An elf what?"
"Just an elf. That's it."
"Well you can't be just an elf, you have to be something else as well. Like a fighter."
"Fighters are humans. Elves are elves. But enough of this. What class are you?"
"A vampire."
(1e paladin) "AAAAGHHH EVIL! KILL IT!!!"
A few moments later
"Well, that was close - why didn't you guys help me?"
"Sorry, I was looking up the 3e grappling rules."
"Sorry, I was scared of being level drained if I got too close"
"Sorry, I was looking in the 4e handbooks to see if I can get to play a beholder."
"Well, never mind. But I'm really badly hurt and out of healing surges. Who will let me suck their blood?"
...
"Well ... sometimes, you just can't hold a paladin back."
"I rolled legitimate pally stats. No help from houserules. I'll have to play a dumb old fighter or cleric next. IT'S NOT FAIR!"
"Should have left me alone then."
"If it lives in a crypt or has scales and a snout, you kill it. No exceptions."
"You wouldn't survive five minutes in Sigil then. Inhabitants like that are on the normal side."
"Yeah yeah ... Gonna roll, be back soon."
"Woot! More hot rolling. I get to be a monk, AND I have psionic powers!"
"Well duh, monks ARE psionic."
(Nearly everyone else) "No they're not!"
(
The Elf) "What's psionics? Also, what's a monk?"
"A monk is a class that's skilled in unarmed combat, plus the use of some special monk weapons."
"Yeah, and he's also kind of a thief..."
Thwack
"Oh no, not again! Why did you do that?"
"I'm not having some stinky thief hanging around."
"Umm - I think he meant to say 'rogue'"
"Oops - sorry. See you with your next character."
"Back again. Now I'm an assassin."
"Assassins don't exist."
"What's an assassin?"
"1st level characters can't be assassins. It's a prestige class."
"Since none of you three think I exist, you ALL DIE! Mwahahahaha!!"
"Oh ... darn."
"OK, just us left. I'm evil. You're evil. Let's go adventuring."
"Umm, I might be a vampire, but I'm actually Lawful Good."
"You're what?! Why didn't you tell my paladin?"
"I would've done, but he was just too Lawful Stupid to listen."