Almost half of the top 10 grossing films this year have been extensions of a franchise. Hollywood blockbuster - the last of a trilogy based on the Marvel Comics character starring Robert Downey Jnr - performed the best, taking in HK$106 million, making it the highest-grossing film in Hong Kong so far this year.

Other top earners - (HK$28.68 million), (HK$28.4 million), (HK$25.37 million) and (HK$24.26 million) - are also sequels.

What the figures suggest is that originality is not necessarily a prerequisite for cinematic popularity. In fact, sequels have been known to rake in much more than the original.

Box office income for , for instance, dwarfed that of the first two, which earned HK$22 million and HK$29 million respectively.

The final instalment is the third-highest grossing film of all time in Hong Kong. It trails only James Cameron's and , which took HK$178 million and HK$115 million respectively. It knocked off last year's smash hit , which grossed HK$97 million, from the top three.

Walt Disney Studios Hong Kong's general manager and vice-president John Hsu says - which saw Downey return as the Iron Man - has piggybacked on the success of .

"To be only the third film in history to cross the HK$100 million box office threshold is not only a testament to the popularity of the character but to the strength of the Marvel brand in Hong Kong," he says.

The action movies have also proved popular

among local cinema-goers.

The HK$28.68 million total take of shows Bruce Willis has lost little of his appeal as the foul-mouthed, wisecracking, no-nonsense action man.

But the timing of the release also helped boost attendance. The fifth film in the franchise, which has Willis' character John McClane travelling to Russia to get his son Jack out of trouble, emerged as the box office champion for this year's Lunar New Year period - a time when local comedies dominate.

That is because the action flick had "the good fortune to be the only Hollywood blockbuster opening during the Chinese New Year period", says a marketing spokesman for Kentac Investments, the film's local distributor.

Similarly, , the third-best performer among the trio of franchise films in the mid-year top five, opened over Easter when "there were no similar movies to compete with it", says Mandy Lam, senior film booking manager at Broadway Theatre Company.

Lam also points to a trend of audiences favouring the tried and tested.

"Hong Kong movie-goers are quite sceptical. They don't want to risk their money watching something they are not sure about. And sequels like and have good track records," she says.

Of the major Chinese-language films, Stephen Chow Sing-chi's performed the best at the box office, raking in HK$28.4 million, and is fourth on the top 10 list.

Though not exactly a follow-up to his earlier films - part one and two in which Chow stars and which were loosely based on the Chinese literary classic - it is nonetheless a rendering of the Monkey King story.

It was released over the Lunar New Year so had to compete with Vincent Kok Tak-chiu's and Chung Shu-kai's

The popularity of sequels comes as no surprise to David Bordwell, a film studies professor at the University of Wisconsin,

who says their commercial success has been one of the most noticeable trends of the Hollywood film industry for quite a while.

"Some of the sequels did better worldwide than the original. It also happened with ," he says.

And the trend isn't confined to Hollywood. "The French have their own sequels, such as the , and series," says Bordwell, whose publications include .

He also says a string of local movie sequels have become silver-screen classics. "The world of film would be a poorer place if critics had by fiat banned all the fine Hong Kong sequels, notably those spawned by , , , , and so on."

Franchised films have fans within and outside film industries worldwide.

"Producers and studios like sequels because they guarantee name recognition; the project is in a sense pre-sold. Audiences like sequels because they usually feature the same stars that they liked before, and they come to the story with some idea about what they are likely to get," Bordwell says.

Sequels such as , , , The Wolverine and have flooded the city's cinemas in the past couple of months. And there are more to come:

, and .

Box office takings aside, are sequels a good or a bad thing?

"The only people who don't like sequels are critics who claim that sequels show a lack of imagination," Bordwell says.

"But sequels and series are an inescapable part of popular cinema, going back to the 1910s, and they don't have to be mere repetitions. The series shows interesting differences among the directors and the trio show an imaginative approach to the central story."

- HK$106.39 million

- HK$40.85 million

- HK$28.68 million

- HK$28.4 million

- HK$25.37 million

- HK$24.26 million

- HK$21.29 million

- HK$20.93 million

- HK$19.44 million

- HK$17.37 million

Source: Hong Kong Motion Picture Industry Association