I attended Dreamin' In Dallas, DARA's Writer's Conference this weekend. It was really a lot of fun. Anyway there was this workshop on TV script writing by Dean Lorey . That's not something I aspire to, but curiosity won out. Here's the rundown on what happens in the writer's room, which is always referred to as just: The Room. Some terms first: Showrunner: Person in charge of everything. Even the director defers to the Showrunner. The SR is 99.9 times a writer, often the creator of the show (whoever writes the pilot). The Showrunner makes the final pass on all the scripts.
Half-Hours: These are the sitcom type shows that are acted out like a stage play in front of live audiences with at least four cameras on them.
One-Hours: Shot with one camera like little movies at different set locations. Has long season arcs, almost like a soap opera. Supernatural is a One-Hour.
This is how the writers map out a One-Hour show's season:
The Showrunner is in charge. It's called "running a room".
Four to Twelve writers sit around a large conference table for about twelve to sixteen hours, pitching out ideas.
The Showrunner picks out the ideas she likes and together the writing staff lays out broadstroke beats for each episode. They make an outline for the season arc.
Then the Showrunner pitches the ideas to the executives. They approve them. Or not.
The Showrunner assigns writers to each episode. (Usually in teams. The entire team is paid as a team, so they split up whatever each episode is worth. Like paying two writers for the price of one. Heh.) Basic episode outlines are handed out to the teams.
Each writing team writes a full outline of their episode and presents it to the Showrunner.
Showrunner takes and gives note. A lot of back and forth goes on.
Writing team then writes the draft for the episode and presents it to the Showrunner, and gets notes until she is satisfied.
The Showrunner gives approval for the final draft and hands it off to the director and the episode gets shot.
While the episode is shooting, the writing team and Showrunner watch the dailies each morning.
Dailies are what was shot the previous day. The team and Showrunner decide if something needs to be re-shot.
Also, the Writer's Guild of America mandates that two scripts per season must be writen by freelance writers. That's why sometimes we'll see an episode od our favorite shows are written by writers we've never heard of before.
Now for a Half-Hour show, the room runs a little differently. Instead of plotting out the entire season arc, they hash out episode by episode at a time collaboratively while the Showrunner's assistant types the script then and there, and is on a screen that the writers watch. These are also the shows that the actors come in to the room and do a run-through with the writers.
So, that's the process of how your favorite show comes into being.