He is Adrian Monk. He is Sam Spade. He is William of Baskerville . He is The Question.
He can be a woman, but is usually a man.
The Detective’s life is defined by Quests that take the form of a mystery.
Unlike a normal Quest, which is to acquire Something or to defeat a Villain, a mystery is a Quest where a Puzzle needs to be solved. To be sure, the solution of the puzzle will often be the fulcrum of the villain's defeat.
The Detective’s moral universe is stark but complex. Good and Evil are distinct but telling one from the other is difficult.
He is vulnerable to the Femme Fatale. He is prone to mistake her for his One True Love.
On those rare occasions where he does find his One True Love, she will inevitably be killed. He will then avenge her.
Unlike other Heroes, the Detective can have many One True Loves.
Not all Detectives are detectives, nor are all detectives Detectives.
Neither Batman nor Sherlock Holmes are Detectives. They are Competent Men.
The Detective is fallible. He can be misled and deceived. He can also fail to get the bad guy. Alone among Heroes, he can remain a Hero even when the Villain wins – at least for the moment.
His life is tragic. It is defined by his mistakes and his losses and much as by his successes.
His friends tend to die. Never the less, those friends he has are loyal to him.
His greatest weapons are his wits and his luck. When things are at their worst, he’s prone to have a Stroke of Luck, often as a result of Thinking on his Feet.
He is street smart. He may also be educated but his most critical skills are being able to judge others, to spot inconsistencies, and to see through deceptions.
He can usually fight but he isn’t a warrior, much less a soldier.
He is lonely.
He is often an atheist although he wishes that there were a God. Above all else, he believes in Justice and despairs of ever finding it.