San Antonio is a terrific dining town. It's big enough and has enough demanding conventioneers to support fine dining you'd usually find in much larger cities. But it still has a relaxed small-town feel that makes it easy to eat out almost anywhere without much fuss. You can count on one hand the number of restaurants requiring jackets; the dress codes at most other nice restaurants pretty much stops at "no shorts, please." Reservations and long waits are rare except at a few high-end restaurants and at peak times on the River Walk.
Essentially, San Antonio cuisine is about two things: Mexican-inspired flavors and meat. Mexican, Tex-Mex, Latin, and a variety of other fusion variations crowd this bi-cultural town. You'll find wonderful Mexican breads and pastries, rich sauces with complex flavors heavy with chilies, fresh peppers, even chocolate. Margaritas and local beers, courtesy of the local German immigrant brewing tradition, remedy the occasional chili overdose (though not all Latin food here is spicy—far from it). If your idea of a perfect meal is a steak, ribs, or just a killer hamburger, this is your kind of town. But San Antonio isn't stuck remembering the Alamo at every meal: chef-driven restaurants with a wide range of offerings, including sushi, offer a break from beef and tortillas.
Most restaurants, especially downtown and at the River Walk, are open seven days a week. Outside the downtown tourist area, restaurants generally close at around 10 on weekdays, 11 on weekends. River Walk restaurants and bars stay open later, generally until 2 am. San Antonio bans smoking in all restaurants except in designated outdoor areas (bars do allow it). Tipping conventions are standard, generally 15% for lunch, 20% for dinner.