Three children are born at the exact same time,during a lunar eclipse.Just before their 10th birthday they embark on a killing spree."Bloody Birthday" is a typical slasher from early 80's.It's a pretty average stuff with plenty of nudity.The evil children never generate any menace and there is almost no suspense.There is also no gore or scares in "Bloody Birthday",but the film is mildly entertaining.Unfortunately no real explanation is provided for the kids sudden homicidal mania.The murder scenes are quite gruesome for example we've got death by handgun,baseball bat,skipping rope and shovel.So if you're a fan of early 80's slasher movies give this one a look.