When this "accidental death and dismemberment" provision is added to a life insurance policy, it usually works like this. If you have a death benefit of X, and you die as a result of an accident, your beneficiary will receive 2X. Some carry extra caveats concerning auto accidents which say that if you die in a car wreck, the beneficiary will get 3X, and if you're wearing a seat belt, 4X.
The dismemberment provisions get tricky. If you lose 2 limbs and survive, you usually get 2X yourself. If you lose one limb, you usually get 1/2X yourself. There has been more than one occasion where a person has chopped off a limb in order to collect that 1/2X. It's the company's thinking that if you have the balls and the ingenuity to chop off two limbs, you deserve the 2X. (Just kidding; if you're going to do this, you must make it look as if it were an accident.)
Oh, and in the accidental death deal, that means a piano falls out of the sky and kills you, or something that is obviously not premeditated. If you piss off a fellow noder, and they work some sort of voodoo and zap you through your zip drive, that's murder. Your beneficiary only gets X.