Earlier this year I gave long answers to some very basic questions for a film student's diploma dissertation.
How would you go about selling a script or concept? Can you sell a concept?
You can sell a concept, and people do it all the time, but it has its hazards. Because, see above - if you've sold a concept then you've then got to find its form with the added pressure of people invested and breathing down your neck. So in my case, when I pitch a concept, I've got the completed plan already thought-out. Not in minute detail, but in the broad strokes. If rushed it's very easy to make lazy choices - of characters, motives, and incidents drawn from other films and TV - and once those are locked-in, you're stuck with them. You'll see many a film or TV show where the one-line concept is intriguing but the characters and situations are all stock.
US TV has a 'pitching season' in the middle of the year when all the broadcast and cable companies open their doors to new material, and producers book appointments to go in with their writers and pitch the show they've been developing together. You get about 20 minutes to explain your show to a listening team of four or five executives, and then it's the next team's turn. Sometimes - rarely - a pitch will be bought 'in the room'. More often you'll hear back within a couple of days, a week at the most.
In the UK it's way less organised. A broadcaster will circulate a note to production companies to say they don't want to see any more crime shows but they're in the market for an inner-city medical series about Travellers. Every producer contacts their regular writers and works up a Big Fat Gypsy Medic pitch. All the pitches come in at the same time. Meanwhile the broadcaster buys something completely different, probably a crime show. I've lost count of the number of times I've seen this happen.
Are there certain rules about production companies wanting in-house staff writers?
The US hires writers and the UK buys stories. Every US show is staff-written with almost no openings for freelancers. There's a 'staffing season' that comes right after 'pilot pickup season', where the showrunners of new shows read script samples and hire that season's team. There's a ranking order to the job titles with Executive Producer at the top, then co-exec, then supervising producer, story editor, consulting producer, staff writer. All are writers, and each will probably have two scripts in the season with their byline. On those scripts they'll be the prime writer, though the story will have been worked-over and beefed up by everyone in the Writers' Room and the showrunner will give it a final pass for style and consistency. Staff Writer is the 'entry level' job. People get to be staff writers by writing 'spec scripts' of shows they don't work on, to show as writing samples. Every writer on the team has a personal project of their own that they someday hope to sell.
In the UK, the episodic series producer will first approach writers he or she has worked with before, and then will put out a call to agents for potential contributors. Then a meeting or a phonecall in which the producer describes the show to the prospective writer, who then goes away and cooks up two or three story ideas. It may go further, it may not. If it doesn't, the writer's been working for nothing. In my experience of such series the writer usually doesn't meet the creator or any of the other writers. In my humble opinion this is a vastly inferior system. The few times I've seen a UK production attempt to imitate the American system, it's stumbled at the British reluctance to commit to a writers' talent and put them on staff to produce material. They want to see the story and then buy it.
Soaps are different, employing storyliners who supply detailed outlines to a pool of scriptwriters, but they still depend on the freelance model. Producers are trusted to be paid a salary for work they haven't done yet, writers aren't.