For the rather "normal" clubs, there are rather strict rules when it comes to applying force of any kind. That already includes a forceful removing of people who are not welcome any more, be it outside and not letting in or inside and escorting out.
The biggest rule really is the proportionality of the applied force. Bruises are nothing to worry about as long as it isn't simply too much or too obvious. Hitting is normally already a no-go. At least most of my colleagues - and you tend to know a lot of people who do/did this kind of job in your region - don't hit people and it's not necessary in 99% of the cases. Which makes sense cuz the common case is some drunk idiot thinking he's the king of the World. He's drunk, slow, uncoordinated and a bouncer is sober and trained in at least some kind of martial arts. Easy...
Difference in the clubs is less obvious than you think for the job itself btw. I've worked casual clubs mostly but had my few instances of dirty pubs and high-class lounges alike. To be honest, the guys in the dirty pubs comply easier than the lounge-pricks. I guess it's about the attitude and experience: people in a pub know the consequences when they don't follow a bouncer when asked to, those wanna-be high rollers think they deserve a special treatment and start cursing you as low-life and what not ("Do you know who I am?" "Well, I know who your daddy is but he's not here now, is he?!") At least for me, it didn't make that much of a difference tho. My common approach was to ask very politely to follow me, there is something he had to listen to and that it was important. 90% would come along. Key is in my experience to be as non-threatening as possible, speak slow, quiet and, as mentioned, polite. The other 10%, well, you already know those who gonna make it hard on you with a short glance... A friend I used to work with (and who does the job still today besides studying) used to simply grab into his jacket, get his black lead-filled gloves out and put them on very slowly
Worked every single time I was with him ^^ He just asked again "Are you coming now?" and they would all go
You grab their arm, apply a bit more pressure than necessary and escort them somewhere less loud and explain them what is about to happen. They rarely start a fight at that point and if they do, you fix them against a wall, on the ground and explain them what you did, why you did it and what is going to happen after they made the situation a bit more complicated
Anyway... knives. Most important thing for the bouncer is to keep an eye on the knife for several reasons:
- Don't get cut (obviously)
- Try to talk him down, explain the mistake he making and the consequences when the police arrives
- Either make him focus only you to allow the 2nd guy to get behind or be the 2nd guy and get behind him
- Defend yourself with any force necessary (this is the part where a bone might crack)
Knives are messy. They are ugly and they are more dangerous than most people think but they are nothing you can't handle with a proper training. I'd expect every bouncer to have the proper training when working a club. Those who don't are stupid.
- When the situation is under control, find the knife!
2 reasons: you don't wanna allow another person to get his hand on it and you need it to show the police what you were dealing with and explain why he can't move his right arm any more due to being dislocated.
I was part of 2 incidents with knives during my "career" and the police is pretty easy going when you call them about a knife attack as long as you can provide a witness and the weapon.
I know about a few who had similar attacks and the guy threw the knife away before he got overwhelmed and they had more issues, even had to go to a court hearing but all of them went home w/o even a slap on their wrist cuz of the police giving a statement in favour and witnesses confirming the weapon.
Guns? Never saw one, never heard about them. Except those tear gas pistols but those happen maybe once every 2 years.
