See, that’s a pun because I’m going to talk about ADs. Get it?
I was watching this week’s Raising Hope, and over one of the producer cards in the end credits I heard a voice (I assume a showrunner) say, “what’s a second 2nd?” Which has to be a hint for viewers to look these things up, because writers are usually on set when the episodes they’ve written are being shot and they can ask anyone. Since you likely cannot, I’ll tell you: a second 2nd is part of the AD crew.
AD stands for “assistant director.” They are employed by the show (not the director) and are a vital part of the crew. On a one-hour drama, there are likely two 1st ADs. One will take even-numbered episodes and the other will take odd-numbered episodes. A director will usually be in prep for a week, then production for their episode, then in post (editing) for the last week. All of these overlap, so at any given time there can be three directors working on a show: one in pre-production, one in production, and one in post-production. The 1st AD will be the director’s right-hand person for prep and tape. He or she will figure out the shooting schedule (scenes don’t tape in order – the AD needs to break down which scenes take place indoors or outdoors, what time of day, which scenes can be shot back-to-back and come up with a schedule that takes into account the number of days on set vs on location and crew turnaround – no taping late at night one day and early in the morning the next, plus how many pages can be shot in a day, stunts, etc.). They will go on all location scouts and sit in on department head meetings when everyone goes through the script and makes sure everyone is clear on what props they’re using, wardrobe, etc. The AD will know everyone on crew and help liase between the director and everyone he needs to work with.
There is usually just one 2nd AD on a one-hour, and they are on set every day. The second AD primarily makes sure the cast is taken care of and where they are supposed to be when they are supposed to be there. This includes wardrobe fittings, hair and makeup, and making sure the trailers are acceptable. They put together the call sheets for the next day and the production reports for the current day, and generally make sure everything is running smoothly.
A second 2nd is someone who is brought in specifically on days where there will be a lot of background actors, to help corral them and make sure they’re taken care of. The vast majority of background are actors trying to get more work, so while they may try to stand out they are very conscientious that they stand out for good things. On shows with a more lax look needed from background (like Jericho, which was set post-apocalypse), there will be a few people who want to have someplace to be for the day and get fed, but are not as interested in being on camera. Corralling all of these people, keeping them entertained while they’re sitting around for hours waiting for their scenes to come up, and keeping them from wandering into the writers’ room and pitching (true story!) is a huge job. It doesn’t help when a scene is set in Kansas in December and we’re experiencing a freak heat wave where we shoot in Los Angeles, so the extras are expected to sit around shivering in huge ski parkas in the 90° heat (also a true story!). Shows don’t need second 2nds every day, but they are an invaluable part of the crew when they’re there.