Everything has "three acts" if you boil it down enough. This probably doesn't yield as much insight into life and cinema as Syd Field hopes it does.

In order to get a movie made, often the movie has to be pitched to people who are... well, idiots. They are not capable of understanding why Taxi Driver's two acts (yes, two!) can be divided by crucial points in the character's development, but they are capable of understanding the rather facile "This is what happens at the beginning, this is what happens in the middle, and this is what happens at the end."

Superman is a good example of a movie that has three clear acts, and not just because of the Syd Field paradigm.

Die Hard is an example of a movie that has three clear acts, essentially sticking to the Field paradigm like glue.

I would place the transitions in Superman at the arrival in Kansas and the arrival in Metropolis. They're three different locations, three different looks, and three different sets of narrative concerns.

I would place the point of transition in Taxi Driver at or around the scene in which Travis attempts to tell Wizard about his problems, because that's the last point where he could have been helped.

I'm a little foggy on Alien myself, but there is one turn of phrase Field has used to describe the final act in his paradigm: the ticking clock. Therefore, I would pick McClane's discovery of the time bomb as, quite literally, a textbook example of a final act transition.

Well the movies cling to formula in general, so once three-act became standard it makes sense that others would slavishly follow it.

I mean 2001 or Once Upon a Time in the West (by coincidence (?) both 1968) can't be three act movies...

Act 1: The Dawn of Man
Act 2: Earth and Space, 11 Years Ago
Act 3: Jupiter (and Beyond the Infinite)

(I haven't seen Once Upon a Time in the West, so I can't comment on that one...)

Why are you lumping the moon sequence and journey to Jupiter together? Different characters engaging in different (albeit similar) activities and I'm pretty sure there's an intermission between the two.

Act 1: The Dawn of Man
Act 2: Moon Sequence
Act 3: Journey to Jupiter
Act 4: Jupiter (and Beyond the Infinite)

-Jeremy

Warning: long-ish post incoming.

Syd Field is the screenwriting guru who convinced everybody in Hollywood that the three act structure is the only way to make a movie. I will humor him for a moment.

In the Field paradigm (horrible word, but he uses it), the first act is about the first quarter of the movie--not the first 10 minutes. The third act is the last quarter, not the last five minutes. This means that half the movie (much less than assumed by WWTDD Guy) is made up of the second act.

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Sidebar: The first 10 minutes has been referred to by Field and the others as the period when the viewer gets to know the movie. By that, they mean that you learn which character types and genre you're dealing with, plus develop a decent expectation of how the plot will unfold.

Essentially, in a "good" movie, the first 10 minutes tells you how the whole movie is going to be. I personally find this cynical and restrictive, but it often proves to be true.

The last five minutes of the movie is the resolution of the final act, where we find out what happens to all these people after their ordeal is over.

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So, in a two hour movie, act one lasts for a half hour. That's when you learn the characters, their wants, their needs, their troubles, their flaws, their virtues, etc. Then, at the half-hour point, a Big Plot Thingy happens that embroils the characters in whatever conflict is driving the movie. Then you're into act two.

In act one, John McClane arrives in California. We find out that he's a New York cop, kind of a loose cannon, he's estranged from his family, and he and his wife have all kinds of unresolved issues. Unbeknownst to them (but knownst to us), terrorists have entered the building. The terrorists meet up with the supporting characters, let them (and us) know what they're after, and along the way we learn that their leader, Hans, is a slick dude with a plan to steal all the doubloons. They're a bunch of organized German guys with guns, so they're probably bad news.

What happens at the half hour mark? McClane, who has been sneaking around, sees Hans paint the walls with so-and-so's brains. BAM. First body of the movie. The getting-to-know-you period is over. Henceforth, McClane springs into action. His goal: kill all the terrorists before they can harm anybody else, including his wife.

To skip ahead to act three, somewhere around the last half hour mark is when there is no longer any possibility of turning back. Something--another Big Plot Thingy--something happens that puts the heroes and villains in a do-or-die, ticking timebomb sort of situation where the conflict absolutely must end, one way or the other.

What happens in Die Hard at the last half hour mark? McClane finds the explosives near the top of the building, a literal ticking timebomb. He now knows that the terrorists never had any intention of letting anybody get out of that building alive, and that the people in the building are under a greater threat than they've previously imagined. There's your do-or-die moment.

So... act two. What happens in act two?

In the romantic sense, you test the characters. You put them in situations that test their physical prowess, their intelligence, their moral fiber, and otherwise prepare them for their big final test at the end of the movie. This is referred to by Field as complication and development.

In the unromantic sense, you just find a number of reasons why the big final conflict can't happen yet. It's a bunch of stumbling blocks between point A and point B. That's it.

We're dealing with conventional movie plotting--in other words, churning out product on an assembly line--so there is no reason to romanticize act two. It's a series of contrivances that puts off the inevitable. It stalls for time.

So no, it is not a big deal that Men In Black III went into production without a second act. Iron Man's script was in a similar condition at the start of production, and that turned out pretty well. Just find some crap to shovel into the middle of the movie. It's not as disastrous as it sounds, at least by tentpole summer movie standards.

Answer me this: is there really a substantive difference between "a logical progression of events where Will Smith figures out how to save Tommy Lee Jones" and "Smith shouting things that really don’t need to be shouted and him telling us how handsome he is"?

I mean really, is there? I offer the previous two movies in the series for consideration.

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Another sidebar: the Field paradigm is commonly assumed to be the last word on screenplay construction, but it really isn't. The trouble with the Field assumption is that it relies on confirmation bias. You can look at anything that begins and ends (and what doesn't?) as falling into three parts in one way or another.

This ignores alternative act breakdowns that spring specifically from the material, rather than some predetermined assumption.

Taxi Driver, for example, has two acts. The first one is about Travis and his struggles to get along in this world. The second is about his great plan to strike back. 2001: A Space Odyssey has four acts, and Kubrick was even kind enough to label them on the screen for our convenience. Superman has three acts, but not in the Field sense. In fact, the third act is by far the longest and most development-heavy of the movie.

When you see a movie that obviously conforms to the Field paradigm (not just for the facile reason that everything does), it's most likely because it was made with the Field paradigm in mind. These tend to be the most commercial, most pitch-friendly movies. That's why I cite Die Hard as an example. It is the ultimate in conventional, formulaic moviemaking.

If a retarded film executive can understand your plot breakdown, you have a much better chance of securing funding for your movie. And every retarded film executive who thinks he knows everything has probably internalized the Field paradigm into his brain chemistry.

Of course there is.

Note also the similarities between sex and telling a joke, playing a hand of Hold 'Em, getting a table at a restaurant...