When you walk in the front door, you enter the first public dining room. Except for the two peak times of the year (Carnival and Jazz Fest), it's not terribly hard to get a table in the front room just by walking in off the street. Unfortuntaely, it's also the source of many of the unfavorable reviews one reads about Antoine's. Coming in off of the street removes many of the aspects of dining at Antoine's that are a part of the overall experience. This room is very bright, like Galatoire's. White walls, mostly white tile floor, and white linen tablecloths really illuminate the front room.
If you have reservations, however, you'll be led through the front dining room and to the right, where you'll be seated in the back dining room. This room's dark exposed beam ceiling, russet-colored walls, and more subdued lighting is where the regulars eat. You get a literal night-and-day feeling when you go from front to back. It's as if the front room is really an extension of the street outside, and moving into the back is when you enter a more private realm. I know regulars who have gone to the restaurant on crowded nights and have been totally outraged that they had to be seated in the front room, in spite of the fact they have reservations! Bear in mind that there's only one kitchen, and the food served to both rooms is identical. It's just that much of a difference in atmosphere.
When the city of New Orleans passed an ordinance requiring restaurants to offer smoke-free dining areas that were truly smoke-free, the character of the Front and Back dining rooms at Antoine's changed a bit. The undesirability of the Front room among regulars has tapered off, at least for those who prefer a smoke-free environment. People who would never consider eating in the area populated by social outcasts are discovering that the Front room is a neat place after all.
Regulars to the restaurant are able to avoid entering the front dining room completely by using the famous "side door" of Antoine's. If you walk past the front doors of the restarant, there's an unmarked door about twenty feet down. This door opens into an access hallway that separates the two main dining rooms from the private rooms in the back. If you have a reservation, you can just walk in this door, and you'll be seated at your table in the back room or in one of the private rooms.