To have fun. Play something different from the norm. Also good/vs evil is not black and white. A character could be convinced he is being heroic and good, and actually be evil (maybe he has no qualms killing the innocent to achieve his virtous goals, or maybe he is overly self serving and selfish.)
This list could go on and on, but this was just some things off the top of my head, and I like to play a mix of good and evil characters btw.
Because Evil characters have less restrictions and are, IMO, more interesting to play than the goody goody gumdrops heroes.
You can play an Evil character with the same goals as a Good character superficially, but the cool thing about Evil characters is being ruthless doesn't go against your alignment really.
Now I like Neutral and Good characters too, but I LOVE Evil characters (especially Lawful Evil).
Sometimes it doesn't fit, but in many cases like in official APs, there's a selfish reason for them to go on the quest anyway, so it doesn't muck with anything there.
You don't get being able to cut loose and wreak havoc every now and then?
Have you ever played, say, Fallout 3 as an Evil character? Blow up Megaton, pay people to fix your items, then kill them and take your money back. Shoot the MIRV (7 mini-nukes) straight up into the air in the middle of a crowded city and listen to the bomb worshiper go "Look, it is coming from the clouds *BOOMBOOMBOOMBOOMBOOMBOOMBOOM*".
That's the Chaotic Stupid party in a nutshell right there. It has to be contained, of course, so it doesn't wreck anything important you wanted to run, but it's always fun every once in a while (okay...every time I played FO3 I was Evil).
It's FUN, because it's something you'd never in a million years do in real life.
And who said anything about 10-11 year old children? I'm assuming you're playing with people your own age here. But here's a hint: Children LOVE PLAYING THE BAD GUY. They get the feeling they're being naughty, but they never get in trouble for it because it's not real.
beep boop why do you hyoo-mons enjoy things
"I twirl my mustache as I prepare for world domination."
"SIR HOW DARE YOU THERE ARE CHILDREN PRESENT"
"I twirl my mustache as I prepare for world domination."
"SIR HOW DARE YOU THERE ARE CHILDREN PRESENT"
STOP IT
STOP BEING FUNNY
I just don't get the ALL evil party and GM. Where's the good story there? Just all self indulgence. Rape and pillage. Who enjoys that?
I dunno but if I had to take a wild guess THE PEOPLE DOING IT.
D&D has always been full of breaking into random people's homes and killing them and taking their stuff, evil parties just get to do it to elves instead of orcs.
It's really icky, last D&D session I punched a town guard in the face and suddenly felt like I really needed to take a shower so I ran away and cried but I couldn't undo my horrible crimes and my god the horror the horror
Confession: once upon a time, I even played an assassin. As everyone knows, the assassin class is only for evil characters, which makes sense because only a vile monster would dedicate their career to killing things. But now I have become enlightened and play a fighter instead, which is better because
Why do you play RPGs aren't they just for nerd losers or something??? I don't get it?????
It might not be your thing. But to get bent out of shape because others like it seems irrational. RP games are largely the draw of playing as a person you just can't be in the real world. Most of the time to an extreme extent. This is just another way of doing that.
You really need to decouple you real world morality from the game. Playing evil does in no way mean someone has any sort of complex. It means they are playing a game.
Game how you like and let others game how they like. There is way to much off this attacking people for not playing "How I think is the right way" going on anymore.