Caper movies are an honorable niche that is full of conventions and which filmmakers ignore at their peril. They can be ridiculous and funny--“Dirty Rotten Scoundrels”-- classic and funny—“How to Steal a Million”—or melodramatic and shocking—“Pickup on South Street”—or any combination. In some the audience knows what is happening and shares the viewpoint of one of the criminals undertaking the heist, such as in “Topkapi”; in others, like “The Spanish Prisoner” the audience is fooled along with the protagonist and is experiences the same surprises and double dealing that he does. But whatever the trappings, caper movies, heist movies and conman movies all share one important trait—the theft of a well guarded and very valuable object or the tricking of a very tough and resourceful opponent is at the center of the story.

Love triangle movies have their own rules but they tend to be much less restrictive—and they include some of the iconic films of all time, including “Casablanca”, “Jules and Jim” and “Gone with the Wind”. Combining the two is difficult but has resulted in some terrific movies, such as “Bob le flambeur” or “Out of the Past”.

As a caper movie, “Once a Thief” fails the most important test—the theft of the valuable object, in this case an absolutely hideous modern painting, is so simple that the thieves are able to go about the robbery with almost no planning. This deprives the movie of the tension and balance that characterizes the best work of this genre. In the first theft Chow Yun Fat and Leslie Cheung simply show up at the chateau where the painting is located, disarm some of the guards (including accidentally knocking out one of them with a grappling hook) scale the walls, find the painting, avoid the pressure pads by swinging from a chandelier and leave, although they are faced with the ubiquitous laser beam security system—which never works in the movies, of course. Essentially they are able to make up everything as they go along—while there are some ingenious touches, such as using a glass of red wine as a prism to locate the otherwise invisible laser beams, Chow and Cheung are having much too good a time to be taken seriously as crooks. The sequence continues with a John Woo convention, a shootout between the ambushed and outgunned heroes and a seemingly inexhaustible supply of bad guys and ends with a decent car/motorcycle chase punctuated by a the fiery collision between a car and a speedboat.

The second heist of the same dreadful painting includes a bit of planning by the now partially immobilized Chow but when an unanticipated change in the security system brings platoons of art gallery guards and hired thugs after them they deal with it by blowing them up with unused plastic explosive. In other words there is none of the creativity, attention to detail and thrilling anxiety that are part of the best caper movies. Whenever a problem comes up they shoot it, blow it up, electrocute it or throw it out of a window.

There is still a good bit to like about “Once a Thief”. Chow Yun Fat is at his most glamorously insouciant, never breaking a sweat even while tossing gelignite at the bad guys and looking positively dapper in black tie even though he is in a wheelchair. Leslie Cheung seems to be at his most attractive here—he was, quite simply, an extremely alluring young actor who exceeded the typical standards of male beauty and who the camera loved. Cherie Chung isn’t given much to do other than look bemused and pensive while waiting for the guys to show up, once at the airport and once at the docks. Her character is a third wheel, tossed into the mix with no real purpose and not even important enough for the boys to fight over.

There are several very well executed and exciting set pieces—the first is the theft of a modern master from a sealed and guarded truck. Leslie Cheung’s character dumps a motorcycle under the truck, hangs onto the undercarriage while cutting a hole in the floor of the trailer, takes the rolled up painting, slices the brake line of the truck then drops to the pavement. Meanwhile Chow Yun Fat leaps to the back of the truck from the hood of a speeding car, finds the crate with the painting and passes it to Cheung. Later there is a dry run at an auction at the gallery where the painting is being housed in which Cheung is able to gain access to the secured areas because Chow is so effective at creating a diversion. This set piece shows the meticulous planning and split second execution that most caper movies demand, but it is the only time it happens, although it shows what Woo could have done if he had wanted to. There is an exciting and inventive car chase, with cars careening down the long steps outside a government building, a car slamming through a travel trailer and the bit with Chow’s car going airborne to smash a boat full of gunmen.

The supporting cast is uniformly excellent and well written, especially Kenneth Tsang as Mr. Chow, a Fagan-like figure who adopted the three when the were young orphans and taught them to be thieves. He is contrasted with Paul Cho Kong’s character, Mr. Chu who is a police officer and the godfather of the three. The two of them run parallel courses, tied together by their continuing interest in the thieves. Mr. Chow needs them to steal (actually to keep stealing) the painting, Mr. Chu wants them to stay out of trouble and also wants to break Chow and arrest him. Pierre Yves Burton is appropriately oily as a French art connoisseur who initially wants the painting stolen but who comes to a fitting end. Declan Michael Wong plays a character who has to be seen to be believed—and then is hard to believe. He is one of Mr. Chow’s thugs but instead of using a gun, knife or hand grenade he has a deck of playing cards that he throws, slicing and dicing his opponents. Since his targets are always Chow or Cheung he always misses but does chop down a few potted cactus plants.

One delightful shot takes place during the final battle between Chow and Cheung on one side and Mr. Chow and his innumerable thugs on the other. Chow has cornered on of the thugs and is poking at him with a pole. The camera is undercranked so that the scene when shown at 24 frames per second is speeded up although it still looked pretty smooth. The thug ducks and dodges Chow’s thrusts, finally moving his head from side to side more and more rapidly, all while a short except from “Carmen” is playing—it could have been the live action version of a Warner Brothers cartoon, with Bugs Bunny tormenting Elmer Fudd to the strains of some (then) recognizable classical theme.