The Doctrine of Double Effect is a principle that allows for the performance of actions that you know will cause harm to innocent people (normally forbidden by our moral obligation not to cause such harm) on the condition that ____

An obscure rule in chess that allows you to take two pawns with a knight whenever a player says, "ballyhoo!" three times in a row while she, at the same time, balances a pumpkin pie on her head and hops from her left to her right foot and back again.

The effect of your action doubles the happiness of all sentient creatues in the aggregate and you intend to bring this effect about by harming the innocent (e.g., harvesting the organs of a useless and unattractive person to save five useful and attractive people).

The harm to the innocent person enacts some fashionable cause promoted by a celebrity everyone happens to like this week.

The harm caused to the innocent is not intended as either a means or an end, but is instead the foreseeable and unintended consequence of an action necessary to promote a proportionately greater good.