He's derided by his superior as a 'blunt instrument', a thuggish action man whose over-reliance on brawn rather than tact makes him more soldierly than suave. He takes taxis while tailing his quarry, fumbles with a defibrillator, is matched blow-by-blow in verbal ping-pong with a female associate, and receives a telling-off for his dress sense.

The name's still Bond, but the 2006 counter-agent isn't the slick James of old.

Or at least he isn't in Casino Royale. A so-called reboot of the franchise, the story - based on Ian Fleming's first Bond novel - sees the British agent at the start of his career, well before he becomes the jet-setting, gadget-wielding, smooth-talking sex pest embodied by the likes of Sean Connery, Roger Moore and Pierce Brosnan over the past four decades. Casino Royale opens with Daniel Craig's Bond not even a double-0 agent yet, still awaiting the first two kills that will give him the promotion he craves.

The pre-title monochrome sequence (in which he duly attains his ambition after finishing off a double-dealing British spy and his associate in Prague) may be inconsequential compared to Casino Royale's major narrative - the new 007, with the support of British Treasury official Vesper Lynd (Eva Green), try to bankrupt Le Chiffre (Mads Mikkelsen), banker to unsavoury warlords and terrorist organisations, at a card game - but it sets the tone for Bond's rebirth.

In several instances Bond seems ill-prepared for his licence to kill: far from an assassin with sangfroid, he is human - and one seemingly psychologically flawed to boot. In an age where heroes are allowed to come damaged - witness 24's Jack Bauer, or Jason Bourne - the new Bond is at once an icon and a fallible mortal, a crucial element in a world that has seen its reality revealed as hardly a black and white affair.

Die-hard fans may be aghast at such a take on Fleming's legacy, but it's this aspect that makes Casino Royale the most riveting Bond film in recent years. Having dispensed with the gadgets and glossy sheen that undermine The World is Not Enough and Die Another Day, Martin Campbell has also injected Casino Royale with grit and grime - the initial action sequence, in which Bond pursues some nondescript villain in a fictional African country, is the embodiment of the franchise's current emphasis on substance rather than style.

And it's substance the cast brings to Casino Royale. The film is vindication for Craig against his critics, his acting engaging the full spectrum of the new Bond's emotions; his on-screen bonding with Green's Lynd is engaging, their verbal exchanges as enthralling as the action. With this aspect covered, Casino Royale surprises by providing more than pyrotechnics and risque revelry on the Riviera.

Casino Royale is screened at limited previews from tomorrow, and opens on Dec 20