There are three main facets to the typical restaurant experience:
Ambiance, meaning the overall feeling of the place. This is shaped by numerous elements, including interior design, seating comfort, lighting, sound level, and even sometimes the nature of the clientele. (A table full of raucous drunks, for instance, generally doesn’t betoken a pleasant dining experience.)
Food (obviously). This is most likely the main reason you came to the restaurant in the first place. A good selection of beer, cocktails, and/or wine — and there are at least 11 ways to tell if a wine is actually good — might also be a factor.
Service. This covers everything from the timing and care with which dishes are served (though these last factors are not always within the server’s control) to the warmth of the welcome and the efficiency and personality of the servers. And some are known for their service — these are the restaurant chains with the happiest customers.
A good restaurant does well with all three on a reasonably consistent basis. It’s certainly possible to have a bad experience in an otherwise admirable eating place — even if it’s one of the best restaurants in America — but it’s the exception, and the restaurant management or staff will usually take steps to make things better.
A bad restaurant may have redeeming qualities — a great view, a nice selection of craft beers, that irresistible artichoke dip — but will almost certainly not leave a good taste in the diner’s mouth, either literally or figuratively.
Of course, it’s not always possible to tell how good the food will be before your first bite, but aspects of the ambiance and service — and hints about the food offered by the menu — can provide warning signs that you’re probably not going to have a pleasant experience.
What to do when these signs are apparent? If it’s logistically and socially possible, just leave. Say you’re sorry; make up an excuse about the babysitter; just get out. If this isn’t possible (you’re embarrassed to make a scene; you’re somebody else’s guest), make the best of it by ordering as little as possible and avoiding potential trouble spots (supposedly fresh seafood, overly complicated dishes). Then eat only what you want, pay the check, and get out of there as soon as you can. You can always stop for a pizza on the way home.