Los Angeles ? A year has passed since Frodo and Sam continued their ominous trek to Mordor. It’s been six months since Neo lay comatose alongside his nemesis. And three more months will pass before the vengeful Bride gets a chance to kill Bill.

Hollywood is in tease mode these days, breaking with the convention that each movie must have a clear beginning, middle and end. Film franchises like “Lord of the Rings,” “The Matrix” and “Kill Bill” are dabbling in installment plans, taking their cue from a serial format that dates back to the ancient Greeks.

“Certainly, serialization of entertainment started with literature,” said Keanu Reeves, who stars as Neo in “The Matrix” trilogy, which concludes with “The Matrix Revolutions,” debuting Wednesday. “The continuation of stories like Oedipus (Sophocles’ three-part theater trilogy). It’s in the tradition, cycles and trilogies.”

The Wachowski brothers shot parts two and three of “The Matrix” simultaneously, a moneysaving method that also allowed them to rush the movies into theaters just a few months apart rather than the typical two or three years.

Likewise, Peter Jackson filmed “The Lord of the Rings” trilogy at the same time, with the films hitting theaters just before Christmas three years running, the final part now six weeks away.

Quentin Tarantino shot “Kill Bill” as one long action tale, then broke it into two parts after he and distributor Miramax decided three hours was too long for a single martial-arts film. Part two debuts in February.

It’s more coincidence than trend that these three projects surfaced around the same time. The stories are epics that needed more than a single movie’s running time to do them justice, and the unresolved endings required the expediency of simultaneous shooting to get them in theaters quickly, before audiences lost interest.

“The Lord of the Rings” had its roots in a grand literary epic. Early on, there had been discussion about compacting J.R.R. Tolkien’s behemoth adventure into one or two movies.

To satisfy fans and do honor to the sprawling story, director Jackson got the go-ahead to divide it into a trilogy, the parts roughly coinciding to Tolkien’s three installments, “The Fellowship of the Ring,” “The Two Towers” and “The Return of the King.” Each movie runs three hours, with extended video versions adding half an hour or more to each.

Hugo Weaving, left, and Keanu Reeves appear in a fight scene from Warner Bros. Pictures action thriller The

“You couldn’t have a 10-hour movie,” said Viggo Mortensen, who stars as the human warrior Aragorn in “The Lord of the Rings” films. “I always looked at it as one story, three movies. I never understood the talk of this whole cliffhanger thing. I would say, people who knew the books wouldn’t have said anything about that. They would view it as one story broken up into three pieces.”

If Hollywood takes away any lessons, it will be on the bottom line, not the lure of cliffhanger storytelling. Whether a franchise is intended as a serialized story or several self-contained films, studios may be enticed by the cost efficiency of shooting two or more movies in one swoop.

While studios can be stuck with money-losing sequels if the first chapter bombs, the strategy can pay off nicely when part one clicks. If “Kill Bill — Vol. 2” matches the performance of “Vol. 1,” Miramax should wind up with a total domestic gross of about $150 million for the two films, a solid return on “Kill Bill’s” $65 million budget.