Your food sucked, your server's attitude hovered somewhere between dismissive and hostile, and if there was an award for longest time elapsed between courses (delivered by the cockroach you saw skitter across the eatery's bathroom wall) this restaurant would win. Hopefully the grand trifecta of dining disasters does not happen to you. And if so, my condolences, and hopefully a trip to a nice Danny Meyer establishment to make it up is in order.

But what if one of the three happens? A more likely occurrence—and one you'd probably consider lowering your usual tip for when the check finally arrives. But do you? While some diners would have no problem leaving little or no tip when bad service is rendered, there are others who know that many restaurant workers rely on tips to make the rent (minimum wage for food service workers in New York is $5/hour; in other states it's close to $3). I almost always, as L.A. Weekly critic Jonathan Gold advises, tip 20 percent, doing the New Yorker shorthand of doubling the 8.5 percent tax amount and adding a bit on top of that because, as my loved ones know, the less math I'm required to do the better.

But at dinner at a sushi spot in Fort Lauderdale, I had a waitress who was flippant to begin with: When asked to return a piece of sea urchin that was clearly not fresh, she said, "Well, some people aren't used to eating sea urchin." That may be true, but I live for sea urchin. If I were on death row, it would be somewhere in my last meal. I've had it in many forms, from the uni and lardo crostini at New York City's Marea, to my favorite, unadorned and impeccably fresh at Azuma in Sydney. To imply that I'm unfamiliar with it isn't only untrue, it's dangerous—especially if I had consumed seafood that was off.

She then became rude when I politely asked that the uni be removed from the check, claiming that any items taken off the bill were docked from her salary. When the check appeared I called the manager, who not only said that the item wouldn't be taken out of the waitress' salary, but promptly removed it from the bill. I left a 10 percent tip, but was upset by the experience.

What would you have done? How much do you usually tip—and what makes you tip substantially lower (or higher) than that number?