Though most of the movie's violence takes place in dreams and is therefore not "real," it includes guns and shooting, gunshot wounds with blood, fistfights, rioting, explosions, car chases, and car crashes.
Does inception have inappropriate scenes?
It does have a great deal of mind-bending action sequences to keep attention on the screen. There's no nudity, I didn't notice many swear words, and the violence is stylized and not particularly bloody. I do think that younger children might either be uninterested in the concept or confused by the layers of dreams.
Can my 12 year old watch inception?
A mature 11 or 12 year old could probably handle and appreciate it, but it's geared teens and adults who are ready to explore ideas about what truly makes a dream a dream.