Special effects are both a gift and a curse. They’re a gift when they can create the stunning, empty vistas of New York as depicted in I Am Legend. They’re a curse when used to create something such as a human-like vampire that could have just as easily been done practically. While the blatantly obvious CG effects take away from the action, they cannot replace or change the intense, emotional performance of Will Smith that carries this sci-fi drama.

Based on a book by Richard Matheson which has been filmed multiple times prior to this 2007 update, the story of the supposed last man on Earth is consistently gripping. Robert Neville is immune to a man-made virus, and struggles to survive in a barren wasteland of New York. Infected people who survived the outbreak, originally thought to be a cure for cancer, have turned into flesh-eating nightwalkers.

Shots of Neville in New York are brilliant. Times Square is now littered with tall grass, buildings are covered with quarantine zone tags, and telephone poles are littered with notes and signs from the religious asking people no longer there to repent. The details are amazing, and immerse the viewer further into the story.

Events that happened prior to day 1,000 of Neville’s sole survivor routine are told in flashback. These are equally intense and involving. However, they’re brief and could easily have been longer. The chaos of the situation, with thousands of the sick, dying, and well converging on a single point is compelling. These shots carry a sense of realism behind them, and the idea that mistakes are being consistently made furthers the pandemonium.

Character development is mostly done in the background. While the flashback scenes cover the basics, numerous little clues are strewn about the frame as to Neville’s history. His refrigerator has magazine covers claiming him to be mankind’s savior. A room in his home is left untouched for reasons revealed later in the film. Small potential plot holes are closed in this manner too, rewarding those paying attention.

Neville’s daily routine is gripping, solely for the fact that he’s alone. It works on an emotional level, as the character's mental status slowly begins wavering. His only companion is a dog and mannequins he befriends. It’s depressing, yet you can’t look away.

Incredible tension is built prior to most of the action. The first reveal of the vampire/zombies is an amazing piece of cinema, putting the viewer next to Neville as he searches a dark building. The images are enhanced by Smith’s performance, which is spot on throughout.

I Am Legend falters when it comes time to view the heavy number of hungry infected. The CG used to create them is unnatural, their movements ridiculous, and it feels unnecessary. To create masses of these sick people, it’s obvious to go the route of computer effects. To use them to create one during a stare-down is painfully obvious. Other botched shots include a helicopter crash with unnatural physics that take away from the emotion of the scene.

I Am Legend never stops being a near masterpiece of sci-fi, but the missteps of the effects are going to turn off a lot of people from this otherwise fantastic movie. Without Smith’s performance, this could have ended up a campy mess. With it, you’ll want to see it twice.