Laura Beck is right — if you’re budgeting to go out to eat, you need to include a tip in that. And you need to tip even if your waitress isn’t as pleasant as you’d like, and even if the service is imperfect. It is a gender issue, and servers (who are disproportionately female) need tips to make a living wage. I also suspect that female servers are more often on the receiving end of a bad tip for not adequately stroking a diner’s ego — not laughing enough at his jokes, not flirting back, not smiling. So tip! Yes, 20%, even if the service was mediocre.
Where I part ways with Laura is here: If the service was legitimately bad, then a lower tip or, under certain circumstances no tip, is acceptable. There was one time in my life where I did not leave a tip. I was trying out a new restaurant in my neighborhood for brunch with two friends. Only one other table was occupied, and the manager, bartender and two waitresses were very occupied with whatever sports game was on TV. We sat down, ordered and waited 90 minutes for our food. During that 90 minutes we asked repeatedly what the status was — if it was coming soon or if we should go elsewhere. We were told it’s “on its way any second.” I also ordered a coffee, which I had to get up and ask the waitress to refill twice (same with water). Each time she looked annoyed for my interrupting her game-watching. Finally, after an hour and a half, our food came — and everything was ice cold. The eggs were congealed. The burger was a hockey puck. So we asked to speak to the manager, explained that we had been there for 90 minutes without food and now were served cold dishes, and said we were leaving without eating. I left $5 for the coffee (and a tip on the service for the coffee and the water).
For me, that’s the level of poor service that it takes to get no tip (or a really low tip). If your waitress makes a racist joke or something, then yeah, no tip there either. And honestly if someone is rude (which happens fairly regularly when you walk into a restaurant with another 20-something woman — the assumption, I guess, is you won’t eat enough) I’ll tip more like 15%. Eye-rolling at the amount we’re ordering, lingering at the bar chatting while our food or drinks are sitting there and we’re waiting, taking away one person’s plate while others at the table are still eating… those things are very annoying and then maybe a tip will be 15-18%, because waiting tables is still a service industry job and part of your job is attending to it without being an asshole. But an insufficient number of smiles or a thing the waitress has no control over (noise levels, the kid at the table next to you) is not a reason to lower your tip. Oh and if you’re doing things that make the waitstaff’s job harder — coming in with a big group, coming in with a kid, staying for a long time — tip more.
Basically, you should be tipping, because someone needs that money to live.