Common Sense Note
Parents need to know that teens might be clamoring to see this movie after the succcess of Underworld and Underworld: Evolution -- not to mention the increased interest in all things vampire thanks to Twilight -- but this is no angsty teen love story. It's an all-out class war between vampires and werewolves, and it's loaded with extreme special-effects violence (from decapitations to being cut in half) and oceans of blood. There's also a sex scene in which little is left to the imagination, but it's more comical than explicit.
Some kissing; a sex scene between consensual adult supernatural beings shields full nudity from the eyes of the audience yet leaves little to the imagination.
Constant, graphic, and gory supernatural violence, including people being cut in half, ripped apart, decapitated, struck by medieval siege weapons (giant crossbow bolts, rocks), stabbed, struck, punched, and kicked. Extensive fantastic hand-to-hand combat, as well as swordplay and neck-biting. Lots of blood, either spilled in combat or drunk as a fact of vampire life. Grisly scenes of characters being lashed as punishment. Vampires are vaporized/immolated by the sun's rays. A character is stabbed through the mouth with a sword, with the protruding blade shown through the back of their skull.
No actual swear words; the clashing characters instead spit supernatural names -- "vampire," "lycan" (the saga's name for werewolves) -- at each other like epithets.
No particularly positive/deep messages here. The vampire aristocrats keep the werewolves in their midst chained as slaves, and there's extensive discussion of their feudal-like system of protection and patronage. A forbidden, wrong-side-of-the-supernatural-tracks romance is discussed at great length. Discussions of infanticide. A vampire calls a servant werewolf "a credit to your race."
Drugs / Tobacco /
None, although blood is drunk in extensive amounts.