The late Sam Fuller, a veteran of moviemaking and of World War II, once said, “Film is like a battleground.” He was commander in chief, his assistant director the general.

On the surface, being an assistant director sounds simple. During prep, the AD drills down deep into the details, figures out the shooting schedule, balances the needs of casting, locations, equipment, etc., tracks and shares all that information and then, on the day, runs the set. (The key second AD and other seconds, plus production assistants, run basecamp, the hair and makeup process, set background, etc.)

The AD is not the director. Directors ask questions like, “Should our heroine drive a sexy, red sports car?” Assistant directors ask questions like, “Can our leading lady drive a stick?” In fact, half of an AD’s responsibilities—the schedule, logistics, safety, budget and time constraints—go beyond the creative and into producer concerns. Producers require an AD’s support as well, but make no mistake, the AD’s allegiance must be clear: Cast and crew will sniff you out in a heartbeat. Are you part of the creative force, or the producer’s eyes and ears on set?

So if you’re reading this as a fledgling AD, take a long stare in the mirror and try to figure out who’s looking back at you. If you’re reading this as a producer or director deciding who to hire as your assistant director, take a moment to consider what you really need. The answer’s probably not your cousin, the guy who’s going to edit the film, or—as I’ve heard people say—“we can just do without.” ADs have very specific skills and experience. They are team leaders as well as team players, great communicators who also understand diplomacy and tact. Shoot days will go sideways, count on it, so your AD must be able to improvise and troubleshoot on the fly. Your AD must also have an eye for detail, since they’re the ones who are going to say “roll camera.” The AD has to like being at the center of the hurricane—sometimes conductor of the orchestra, other times the elementary school playground monitor.

I believe that ADing is a lifestyle, not a job. So whether you are an AD, about to work with one, or just a director who wants to run your set better, here are some things you need to know.

1. First and Foremost, an AD Must Ask Great Questions. Of everyone. And then take notes. Do your own script breakdown; it’s the best way to imprint the film on your brain. Detail as many items as possible and then share those details with the department heads. It does no good if you wrote down five sets of candy glass windows for the stunt sequence, but come to find out on the day that the art department only had the budget for three.

2. Check and Double-Check Timings. For at least the first week, or more when you’re starting, keep a book on the day. Get a small spiral notebook and write shit down. How long is the prosthetic make-up going to take? How long do you need to build the Technocrane? What is the actual flight time on the drone, and how many batteries do you have? How long did that actor take in hair and make- up? When did we start the set-up and when did we finish it? How many takes does the director average? Are the cameraman’s estimates accurate, close or way off the mark? Does he tweak after the first take? All of this practical data allows you to manage the ebb and flow of your set, and hard numbers go a long, long way when you have to go to the producers and explain why you won’t complete the day’s work.

3. Use Actual Hard-Copy Call Sheets. Yes, PDFs will be emailed and you could tweet general call times and locations, but it will be your word against the leading man’s when he says he never got the email, and that’s why he’s an hour late to set.

Brian De Palma, Tom Cruise, and Producer Paula Wagner know that running a well-oiled set isn’t Mission Impossible. Image Courtesy of A24

4. The AD is the Last Word in Crew and Set Safety. If it’s not safe, don’t let it happen. Better to be fired then to live the rest of your life with regret, or worse.

5. Getting Started Smoothly out of the Trucks is Always a Challenge. Knowing the first set-up for the next day is the key to getting the crew moving in the right direction. The best way to do this? Use an actual call sheet and go over it with the director and DP at wrap.

6. Get Your Prelims Out Early. (It’s OK to just email these.) Yes, there will be mistakes and things will change. Preliminary call sheets are, obviously, there as a heads up for the crew, because most will never read the full schedule that you slaved over. Think of prelims as an AD’s early warning system: The remote-control snake puppet was discussed in the production meeting, but only once it lands on the prelim are you likely to find out that the prop master and the producer have been battling over costs and that what you’re really gonna have tomorrow is a rubber snake in the grass.

7. The Phrase “Knowledge is Power” has Deep Roots in Filmmaking. Certain ADs, as well as certain producers and directors, think that holding onto knowledge makes them more powerful. Communicate. Another classic axiom also applies: Assumption is the mother of all fuck-ups. So let fear of public humiliation be your motivator, and you’ll do just fine.

8. Take Your Time Climbing the Ladder as an AD. Being a second second, then a key, learning the ropes, doing call sheets, setting background… that’s how you earn your stripes. Those experiences are what will give you the ability and fortitude to lead a crew and assure the director that your plan is the right plan. Plus, the longer you’re a second, the more first ADs you have the chance to work for and learn from (both what and what not to do).

9. Lastly, the AD has to be the Optimistic Pessimist in the Middle of a Self-Aggrandizing Group Hug. Even though you’re cheering on the troops and predicting total victory, you need to have escape routes for when the cops show up. MM

Jon C. Scheide has more than 200 credits as an assistant director, producer, and director on features, commercials, and web series. This article appears in MovieMaker‘s 2018 Complete Guide to Making Movies