Waiters gets angry and starts arguing with you if you don't tip, it is as close to mandatory you can get without making it illegal.

Let them yell. If they gave you such bad service that it comes to that, it's not like you'll be coming back to that restaurant anyway. I have refused to tip a handful of times and not once have I had any desire to return to those restaurants. They could burn down for all I care.

You walk out the door. Or you wait until the server is away from your table before walking out the door if you don't want to risk confrontation.

Fall on the ground and knock over a table, claim the waiter shoved you. Demand a free meal from the manager. Win win!

I'm kidding about the above, but to be honest, you just don't say anything. The likelihood they're gonna slash your tires or something on your way out isn't even a possibility.

you still don't have too

In theory Yes. In practice, do that to a waiter and if they remember you next time, Good luck eating that food. Tipping is seen almost as an entitled benefit now but provided by the customers instead of employers. It is a lose-lose situation for the customer and employee because waiters get paid like shit by their employer while customer has to cough up the "tip" regardless of how they felt about the food and service.

Why would you return to a restaurant where the service was so poor you didn't feel like leaving a tip?

I've not left a tip a handful of times over some exceptionally bad service and food and never felt the desire to return to those restaurants.

I had thought the same, but a year a later that waiter was working at a different restaurant, I like. Needless say I have very distinctive hair. whether or not they remember me because my hair or not leaving tipping I don't know.

Still was interesting they remembered me a year later from a restaurant I only went to once.

A waiter sees hundreds of people every single night. Unless you were particularly rude or did something memorable, I don't think they'd remember. People always believe people are paying more attention to them than they really are.

Hell you probably weren't the only person not tipping that same night.

True, but you may not want to return and receive service from a waiter whom gets combative over how little you tip. As another person who has worked both front and back of house, I’ve seen and heard some pretty awful stuff.

This is particularly why I hate the new custom of tipping before even receiving service or food. You have to do some game theoretic dance to decide whether you’ll get bad service if you tip low up front vs get bad service anyways because they’ve already got your money.

From reading many threads about this kind of thing: tips in the US rised in recent years. In many places if you only tip 10% you're being asked what was wrong with your food (don't dare to only tip 5%!). 15% is considered mediocre, 20% is baseline "all good". 25% starts to be on the "very good" side.

It's really weird to me how recommended tip levels have shifted in my lifetime (really in the past 15 years):

When I was a kid in the 80s/90s, 15% was standard (there was even the mnemonic to calculate it: 10% is easy to calculate, then take half that and add it). 18% was for really outstanding service, 20% was for outstanding service when someone wanted to show off, and 25% was basically unheard of besides some gossip mag detailing how rich a celebrity was ("They tipped 25%!")

Now I see tip amounts that default to 20%. My hypothesis, and perhaps this is a relatively sad commentary in the US, is that the level of inequality in major US cities is off the charts: for many people eating at a nice restaurant in a major city, food, even eating out, is a tiny portion of their overall budget, so adding 5% is really nothing, but people working in restaurants are really struggling to get by (and diners know it), so the increased tip rate is basically a consequence of trying to make unaffordable large cities bearable for workers.

Yeah I remember distinctively that 10% used to be the go to. Then one day I mentioned that to someone and they balked and just said "Only?" I said that's fair isn't it? They said I should be doing at least 20% minimum. Ever since then I've just stopped going to places that require tipping. I just hate it. I hate knowing when to tip, who to tip, what if someone else sees me tip something that might be too low, someone balks at how much I tip. I just hate it all around. This is why I never if at all go to places that tip. I like to stick to places where I know what I'm gonna spend the moment I place my order. I don't even care if I gotta drive myself to get my order. I just hate dealing with tipping culture in general. It places a cultural onus on me that places me in a situation that I want to avoid entirely.

If you see "gratuity" on the bill, that's a required tip. From what I remember they're usually only added for large groups though (like 6+ people).