The filmmaking techniques employed in the city's action movies are highly valued by mainland audiences.

Last year, action movies took four positions among seven Hong Kong-mainland coproductions in the top 20 blockbusters list.

Hong Kong director Dante Lam's Operation Mekong was the most prominent, pocketing 1.18 billion yuan.

Chen Tak-sum, a veteran Hong Kong action movie director, has embraced the dynamics of cross-border productions: "Action films are a relatively good fit when it comes to cross-cultural productions."

Chen's latest cross-border title Kung Fu Jungle, starring Donnie Yen and Wang Baoqiang, did well with global audiences, generating more than $100 million in worldwide box-office revenue, according to Box Office Mojo, which tracks box-office records.

This is especially true for the mainland. "The (martial) arts fights between characters, together with a reasonably straightforward storyline, can break the language and cultural barriers across the border," he said.

Crafting a whole

As much as many coproductions are setting the bar for plentiful returns in the mainland, filmmakers never consider them easy money.

Looking back, not all epic coproductions have been a guarantee of success. The Great Wall, the Sino-US movie directed by Zhang Yimou with a budget of more than $150 million, wound up a box-office flop. Industry observers believe it lost more than $75 million.

"The crux of making bestselling, cross-cultural movies is to find a topic global audiences really care about and are interested in," said Chen Yiqi, chairman of the Sil-Metropole Organisation, a Hong Kong production company.

"You can't simply win over viewers from other parts of the world just by casting a mixture of actors from the mainland and abroad."