The Play's the Thing
The stage is a magical place. Live actors and a live audience make for an immediacy no other art of the written word can duplicate. The ancient Greeks and Romans believed that the dramatic "poet" (that's us) had the power and the duty to "teach and to please," and it's a tradition that lives on to this day. Sounds great. But how do you do it?
Before your play can teach and please anyone, you have to write it, rewrite it (probably over and over again), submit it to theaters and hope that one of them will want to produce it. It can be a long road, particularly because now more than ever, plays tend to get plenty of development (i.e. readings and workshops) before getting fully produced. Good playwrights typically have patience and perseverance to spare.
Types of Plays
Plays come in all shapes and sizes. Here are the most common ones:
Ten-minute plays have become very popular in recent years with the advent of The Actors Theatre of Louisville contest. A good ten-minute play is not a sketch or an extended gag, but rather a complete, compact play, with a beginning, middle and end. It typically takes place in one scene and runs no more than ten pages. In fact, because many contests disqualify entries with more than ten pages, it's a good idea to adhere to that page limit religiously.
One-acts can run anywhere from fifteen minutes to an hour or more. While technically, the one-act gets its name from having only one act (however long that might be), it's more commonly thought of as a play that isn't long enough to constitute a full evening. Arguably the most popular length for one-acts is around a half-hour. At this length, a play can fit on a bill with a pair of other one-acts, and if your play is suitable for high school production, thirty minutes is a good length for a competition play.
A good one-act focuses on one main action or problem; there's not time to get into complicated layers of plot. And for practical reasons, it's a good idea to keep your play to one set and as few scenes as possible. Why? Let's say that your one-act is on a bill with two other one-acts, a common scenario. Let's further say that your one-act has two distinct settings, requiring two different sets and a set change in the middle of an already short play. Not a good thing. Each of the other one-acts already has its own set requirements, so suddenly the theater is faced with building four different sets for one evening. Not likely to happen.
Another common situation is that a one-act precedes a play that's not quite long enough to be an evening unto itself. My play The White Pages opened for Steve Martin's Picasso at the Lapin Agile and had to make use of largely the same set, with canvases painted like bookcases and a desk brought on to make it look more like a bookstore. So the moral of the story is to write your one-act with the most minimal set and technical demands possible.
Full-length plays are also called evening-length plays, because they're long enough to be their own evening. How long is that? Anywhere from around seventy or eighty minutes and up. How up is up? These days, with TV shrinking our attention spans, you'd better have a very good reason to keep an audience in the theater for much longer than two hours. And it's always a good idea to write your play so that it can be produced, if necessary, with minimal set and technical requirements. This doesn't mean that an ambitious designer can't go to town on your script if that possibility exists, but if producing your play requires eight set changes or filling the stage with water, most theaters will not be able to afford you.
Musicals can run the gamut in length from ten minutes (though these are rare, because it's not very cost effective to assemble a band to play for only ten minutes) to three hours. Again, the middle ground - somewhere between ninety minutes and two hours, is probably the one to shoot for.