The tag line for “Spy Game,” the enjoyable new thriller from director Tony Scott, reads as follows: “It’s not how you play the game, it’s how the game plays you.”

You can just imagine a bunch of ad executives patting each other on the backs for coming up with that witty zinger.

Surprisingly, this line actually fits the film like a glove. Starring Robert Redford and Brad Pitt, “Spy Game” mixes taut action and brisk pacing with a sharp, intelligent look at the morally compromising undercurrents of the dark world of espionage.

Brad Pitt plays Tom Bishop, a young spy working out of Hong Kong two years after the fall of the Berlin Wall. After a rescue attempt in a mainland Chinese prison goes terribly wrong, the Chinese government captures Bishop, imprisons him, and plans to execute him in 24 hours.

Meanwhile, back at CIA headquarters in Langley, Va., top officials worry that Bishop’s arrest and any subsequent rescue efforts will compromise a pending trade agreement with China. It is up to Bishop’s former mentor, a soon-to-retire spy, Nathan Muir (Robert Redford), to figure out how to save his protege. As Muir tries to bend the rules and manipulate his superiors, he subsequently recalls his relationship and past experiences with the rebellious Bishop. These flashbacks ultimately reveal the motivation behind Bishop’s mysterious mission.

Political intrigue is what Scott does best. He gave “Enemy of the State” and “Crimson Tide” a slick, fluid jumpiness that enhanced and energized their cliched technology and corrupt use of power jargon. In “Spy Game,” Scott once again delivers the goods, using quick camera movement and sharp editing to keep viewers on the edge of their seats. At times, he gives the film too much of a techno-jolt. Occasionally the action freezes and a clock pops up on the screen; this visual trick is an unnecessary boost to the suspense already surrounding Bishop’s pending execution. Luckily, the brilliantly executed flashback structure lifts “Spy Game” above Scott’s previous endeavors: Redford and Pitt’s action-packed spy adventure flashbacks balance perfectly with the claustrophobic present-day office intrigue.

Based on their “A River Runs Through It” collaboration, it is no surprise that Redford and Pitt know how to work as a team. They make a wonderful pair, bouncing off each other with father-son playfulness, or in this case, experienced teacher-naive student comraderie (it also helps that they look remarkably alike).

Redford gives the gritty drama a surprising comic charm. Muir is brazenly self-confident in the flashbacks, executing his spy-duties without question or remorse. In his present-day CIA shenanigans, he dances around his superiors with dry wit and ease. The fact that Redford is able to lace these scenes with comedy as well as nail-biting tension is a tribute to his often-understated talent.

Pitt, meanwhile, once again proves that he is the most underappreciated actor working today. Yes, the guy has made bad choices — I don’t think I could sit through “Seven Years in Tibet” or “The Mexican” if you paid me — but he is one of the few actors who make each and every performance look effortless. As Bishop, he delivers just the right amount of moral chutzpah and ambitious intensity.

In the end, “Spy Game” is a great thriller because it is not afraid to pause and reflect on the ideas the thrills are eliciting. As the fast-paced flashback sequences pose questions, the more stagnant present-day thrills offer answers and reveal contradictions. Muir defends “the game” as he trains the young Bishop while he bends the very same rules in order to save Tom in the present. Thus the genius of the tag line “it’s not how you play the game, it’s how the game plays you” falls into place in the end: do you follow the rules and question your morals, or do you manipulate the game and follow your heart?