Yep, picking a fight is kinda dumb and childish.
However, If it's self defense then there are no rules.
Gun, sword, knives, explosives, ball bats, cars, trucks, bow and arrow, pepper spray, french fry vat cleaning rod, rabid dogs, hairspray can and a lighter, a big rock, a chair, hydrochloric acid, doesn't matter. In self defense your job is to stop the person attacking you by any means necessary.
I usually keep a boiled egg in the pocket of my hooded jersey and pajama pants when I go to clubs. This way I can eat it really fast while running away from the attackers. I like to lead them into the girls restroom because half the time they won't go in, and if they do the jokes on them. I start farting hard and fast from the egg I just scarfed down that way the smell over-powers them and they drop like flies. If any of them are still standing after this I put my hood up so I look like a chubby rocky balboa and start screaming "Yo Adrian". This usually buys me just enough precious seconds to flip out my penis and threaten the attacker with pee. If this isn't enough, like say if the guy left trying to attack you is a cross-dressing chubby chaser and he actually starts making sexual advances I punch myself in balls and scream "rape". This not only alerts other people in the bar as well as the bouncers and staff, it also causes my voice to be of a higher pitch to make myself more believable. You could always avoid the entire ordeal by just walking away or calling the cops, but who wants to go through all that trouble?