From Smokin’ Aces’ opening scene, in which a pair of weary-eyed FBI agents in a surveillance van trade jabs, director-screenwriter Joe Carnahan shows his understanding of a fundamental yet oft-overlooked rule of ensemble action/horror films: Flesh out your characters before you rip the flesh off of them. When Las Vegas entertainer-turned-mobster Buddy “Aces” Israel (Jeremy Piven) becomes an FBI snitch, a million-dollar bounty is put on his head; within hours, seven hitmen, a trio of bail bondsmen (led by a mustachioed Ben Affleck), and what appears to be half the FBI (including Ryan Reynolds and Ray Liotta) descend on the Lake Tahoe resort where Israel and his bodyguards are hiding out. It’s a simple setup, but Carnahan—whose only previous work of note is the 2002 crime-drama Narc—isn’t willing to rush things for the sake of getting straight to the action. Instead, he allows each member of the cast to establish his own personality and plan of attack—all the while making it clear that, once the bullets start flying and the bodies start falling, everyone is fair game. The buildup toward Smokin’ Aces’ high-octane battle royale is punctuated with short bursts of stealthy action involving retractable blades and silenced pistols, but when all hell finally does break loose, the film delivers on its promise of over-the-top violence. Machine guns, chain saws, and a 50-caliber sniper rifle provide Carnahan plenty of options with which to quickly yet stylishly dispose of his carefully constructed characters. Only when the smoke clears does the movie falter: A heavy-handed plot twist and a leading character’s role-reversing change of heart ends an otherwise neatly organized film with a head-scratcher. But for a film with so many players and such a frenzied pace, Carnahan’s ability to leave his audience feeling anything other than shell shock has to be considered an achievement.