Cut'n'shut,

RE: ESB

You are describing what happens in three parts of the movie, but you are not explaining WHY the Acts are defined by whats happening in those segments. As that one guy says, Acts are more than a "Beginning, Middle and End" because lunch lines have Beginnings, Middles, and Ends.

What do you see as the "central problem" the one that drives all three acts, in ESB? Start there and work your way back through the Acts. It can sometimes be hard to identify the central problem, and an easy trick is to ask yourself, "What is resolved in the third act?" and that will narrow it down right quick.

RE: 5 Acts vs 3 Acts + Pro/Epilogue

It's really the same thing, you're right. But since 5 act is so rare in modern filmmaking, I think it makes sense to refer to the central 3 Acts still as Acts 1-3, since those 3 Acts are the 3 Acts from 3 Act structure.

Here's Freytag's pyramid. It shows 5 Acts, but most modern movies ignore 5 Act structure, and just focus on the central 3. So, for the sake of comparing the odd movie that has 5 Acts to the rest of them that have 3 Acts... We want to compare "the problem gets worse" to "the problem gets worse" so we say Act 2. Even if that's really Act 3 in the 5 Act structure.

You feelin' me?

Darth Vader [has] no character development [in ESB].)

You're joking, right?