Doom's honor code led him to save Captain America from drowning because Captain America had earlier saved his life, and on another occasion he thanked Spider-Man for saving him from terrorists attacking him in an airport by allowing him to leave alive despite Spider-Man subsequently insulting him. His code of honor also means that he will not attack a respected opponent who is weakened or at a severe disadvantage, as he regards any victory resulting from such circumstances as hollow and meaningless. He has even on several occasions battled opponents who were intent on killing the Fantastic Four, for no other reason than the fact that he does not want the ultimate defeat of the Fantastic Four to come from anyone's hands but his own.