Okay, in chapter 5 of Save the Cat, “Building the perfect Beast,” Blake Snyder waxes eloquent on The Board. I’m going to skip all of the superlatives, glowing praise, and industry anecdotes for now, and get down to describing the core idea.
You set up a big, flat, vertical working space – Blake prefers a corkboard that he can pin index cards to, and use this to arrange your story ideas on. It’s a way of working with the screenplay structure that’s visual, tactile, and ‘a great time-waster’, except that the point is that the time isn’t actually wasted, in the end. It’s just being put to a use that isn’t immediately obvious, because as you play with the board and keep rearranging things, the ideas are being arranged and correlated by your subconscious mind in a way that you could never achieve with conscious disciplined hard work staring at a blank Celtx screen.
Like a lot of Blake’s notions, the Board is fairly structured. He sets it up in four rows of approximately ten scenes each, (plus or minus one spot per row, but still to come up to a total of forty scenes per screenplay.) The timeline of the movie gets arranged on this board a little like a really huge Fan expo autograph line, going left to right across the top row for Act One, then turning the corner, going back the second row and across the third for Act Two, then back the bottom row for Act Four.