The latest film adaptation (and only one to bear the name) of Richard Matheson's novel I Am Legend.With its release came four short animated movies which tell unrelated side stories about the rest of the world.
Badass and Child Duo: Anna and Ethan are a rare Gender Inverted version. While we don't see her fight much, the two of them came to New York from Maryland, across a wasteland infested with Darkseekers. The two of them were from the same group of refugees, and survived by dint of being immune to the airborne strain of the virus.
Big Applesauce: As noted on that trope's page, the setting was moved because the visual impact of an empty New York is more effective than Los Angeles, the book's setting.
Bittersweet Ending: Neville kills himself to allow for the survivors' escape. It's implied that they managed to create the cure afterwards. Then again, like Focus Group Ending below shows, it was not like that originally.
Booby Trap: Dr. Neville's zom... er, infection victim traps. The Darkseekers eventually learn to set traps themselves.
Catapult Nightmare: Averted; Neville wakes up from a nightmare by quietly opening his eyes, as a normal person would do.
Contamination Situation: Sam, the dog, is infected with a virus that turns her into one of the mutants. Robert Neville has to strangle his her before she fully turns and tries to kill him.
Cosy Catastrophe: Robert Neville lives in relative peace and luxury in his house, even playing golf and browsing through video stores.
Crazy-Prepared: Dr. Neville, going home at night and also blowing up his house. He also keeps a rifle in an umbrella stand, and hides weapons including the grenade in the finale in random drawers throughout his house.
Creepy Doll: Well, Creepy Mannequin anyway: If you watch very closely, when Neville sees Fred out in front of Grand Central, Fred's head turns slightly to look him in the face.
Cure For Cancer: The start of the zombie apocalypse, as it was a viral injection that would kill cancer cells. Unfortunately, it kills living cells, too. And then brings them back...
Dramatic Sit-Down: Robert Neville has a moment like this after his dog is infected by the vampire disease and he puts it down. The dog was only companion for three years during the vampire apocalypse. The following shot is of Neville sitting in his car after burying the dog's body and blankly staring at the now empty passenger seat. He almost commits suicide when two unaffected survivors show up and help him.
Evil Brit: Averted; Dr. Krippen didn't mean to create a virus that nearly annihilates the human race.
Flashbacks: Tells how his family died and why he's stuck in New York.
Focus Group Ending: Infamously so, ruining most of the Foreshadowing and creating a few Plot Holes. Originally, Neville would have realized that the infected are intelligent, and just want to take back the flock member he has in his captivity in order to test his cure. A shocked Neville allows to them do this, after which the infected leaves without causing further trouble. The whole event makes Neville start to question his own morality, when the implications of what he has done to develop his cure dawns on him. In the final version of the ending the intelligence of the infected is just implied, but ultimately ignored, and Neville makes a Heroic Sacrifice to help the others escape with his cure. The original ending was eventually included as bonus material on the DVD, where it was named the "controversial" ending.
Foreshadowing: The film demonstrates a bit of it, but the ending's change rendered the Foreshadowing null.
Gender Reveal: Right in the middle of the Tear Jerker that is Sam's death, Neville uses her full name for the first time, somehow making the whole thing even more devastating:
He Who Fights Monsters: Done more subtly than in the novel, the camera pans to the dozens of infected that Neville killed doing experimentations on when he does the same to the one he's currently working on. Anna even looks on with horror when she sees the failed experiments.
"It" Is Dehumanizing: Anna watches Neville experiment on a captured zombie, and asks whether what he's doing will "cure her." Neville responds "Actually, it will probably kill it," with the second "it" slightly emphasized.
Manly Tears: Neville sings Bob Marley's 'Three Little Birds' to Samantha as he holds her in his arms. When she begins to attack him, he strangles her and weeps. The next day, he walks into the video store and breaks down when he finally talks to the girl-mannequin.
"Don't worry... 'bout a thing... 'cause every little thing, is gonna be alright..."
"I... I promised a friend I would say hello to you today... Please say hello to me... Please say hello to me..."
Mind Screw: Fred the Dummy. Neville is less than pleased to see him outside the store.
My God, What Have I Done?: Similar to the He Who Fights Monsters entry, it's rather subtle in the original ending; after returning the mate to the alpha male, Neville looks over at the wall containing pictures of past infected who died in his experimentation.
Never Trust a Trailer: The commercials suggested the film was an action thriller instead of the slow horror-drama it is.
Our Vampires Are Different: The infected creatures. They display characteristics that are a cross between vampires and zombies. Their skin, which is pale, is harmed by sunlight, they're incredibly fast and strong, they have a decayed appearance, are hairless, and spend most of the film acting like stereotypical fast zombies. Except that they have rudimentary intelligence and feelings for each other...
Sanity Slippage: Mostly happens before the "current" time of the movie, though it gets really slidy after Neville is forced to mercy-kill his only companion, the dog. Talking to your pet? That's fairly normal even now. Talking to a mannequin? A little odd. Expecting, nay, begging it to talk back? (See Manly Tears) Yeah, you're pretty far gone. Spending three years as the only uninfected human in New York City, hell the entire world, or so he thinks, will probably make you a little unstable. There's also the fact that even when reunited with other humans he still seems a little broken. Among which being the refusal to think that other humans even could be out there or that the infected aren't the mindless beasts he thinks, despite ever-growing mountains of evidence otherwise, and going blank as he spoke along with the movie Shrek in a way that would make Pavlov proud.
Scenery Gorn: Much of the movie dwells on the spectacle of New York returning to nature and the traces of the desperate last days e.g. the blown bridges. The portrayal of the vegetation, contrary to popular belief, is actually quite conservative. In reality it's likely that the speed of New York's reclamation by nature would be much more thorough by three years later. As one example, if such an extinction were to occur there would be no one to man the water pipes underneath the city, the subways would flood within a week and almost all of the surface streets would cave in from the erosion. As a rich pool of nature right in the middle of Manhattan, Central Park would also increase the rate of reclamation.