[[caption-width-right:211:Hey, at least he's fair.]]
->''"Good and evil are just words. Power always wins."''
-->-- '''Dracula''', to Trevor Belmont, ''VideoGame/CastlevaniaJudgment''
"I am stronger than you, therefore, I make all the rules." This very simple aphorism can be used by a character of virtually any level of intelligence. Whether it's the thug with a club or a super genius with a kill sat, it is the same. Their power justifies whatever it is they do.
Remember that physical strength is not necessarily the determinant here. Monetary wealth, political power, and just about any form of bullying can take the place of this. (Not that any professed adherent to this will necessarily admit it; the bully who uses physical strength may regard an ambush or other clever plan as ''cheating.'')
TruthInTelevision for the vast majority of human history, including today. Fortunately for those of us living in RealLife, the whole idea of [[KnightInShiningArmor Knights In Shining Armor]], True Warriors, and "ComesGreatResponsibility" is to espouse and encourage the ''virtuous'' use of power. The truth is that "Might" is a weapon like any other: its effects depend on s/he who wields it. It ''is'' possible to use might for good.
War, however, is extremely expensive, both in terms of actual money and in terms of human lives, and tends to leave both sides the poorer for it, which is why people are generally encouraged to settle conflicts with something ''other'' than their fists. This is where the "violence is evil" underlying assumption comes from: someone who resorts to violence must be too stupid to use any of the more peaceful conflict-resolution tools. Or worse, are actively looking for any PretextForWar. People and countries are often more than happy to use it as long as they're the ones with the power, but complain when it is applied to them.
Fictional characters taking this trope seriously can lead in all sorts of more specific directions:
* BlindObedience (from everyone weaker)
* WrittenByTheWinners for historical cases.
Opposite hero trope:
* RightMakesMight: Good always triumphs!
See also AppealToForce in LogicalFallacies. TheHedonist, when they are a powerful character, will usually use this logic. Related is MutuallyAssuredDestruction, when both sides are so powerful that peace is maintained precisely because both sides are too mighty to fight without destroying everything they were fighting for.