The Writers Guild of America has asked its 12,000 members
to stop working and set up picket lines.
Late-night television chat shows are likely to be the first productions
to suffer with drama to follow if the strike drags on.
The last strike by screenwriters, in 1988, lasted a crippling 22 weeks.
The BBC's Peter Bowes in Los Angeles says the strike
is expected to have a ripple effect throughout Los Angeles
with businesses that rely on the entertainment industry being hit hard.
He says one estimate puts the potential cost to the city at $1bn.
