First I must apologize to anyone who read the response that Exodus made to this post before I moved it. The "spirit" of his response was correct but technically his response was wrong. No, you may NOT return fire from an elevated area even if you are defending yourself from an attack. As in real life warfare, having the high ground gives one the advantage. Most of the time having the high ground will give you the ability to survive such an attack fairly easily which is why the rule stays in force. There will be rare occasions though where having that high ground does not adequately protect you and you will then be at a disadvantage because you cannot defend yourself until you have come down from the elevated area or until the threat is on equal groud with you. That is life...it's not always fair. Rest assured though, you will not always be the one on the cliff being attacked. You will sometimes be the one down below attacking and as long as we enforce this rule uniformly, in the long run, it will treat everyone fairly. It is just human nature that we only recognize the unfair situations when we are the one at the disadvantage...but it does work both ways.
The only exception to this rule that is understandable is in the situation where a player gets thrown very high in the air because of a close encounter with an enemy hog or some other violent situation. While falling back down to, what is a certain death, you can get off a nade or two to try and take your attacker with you before you die. Other than that though you cannot fire or nade down at any time. Hope that helps.
