All the rules of Harry Morgan's code

In Dexterthe titular serial killer operates under a strict code given by his adoptive father Harry Morgan, with these rules guiding every aspect of Dexter Morgan's life. Dexter Morgan developed a homicidal Dark Passenger after being found in a pool of his murdered mother's blood as a child, with his police officer father, Harry Morgan, eventually teaching him a set of rules that play on his overbearing desire to kill for good. While Dexter's guidelines help prevent him from getting caught, they also provide him with a moral code used to justify his murders.

Dexter Season 8 reveals that Harry's Code was developed by Harry Morgan and Dr. Evelyn Vogel, who realized that Dexter exhibited sociopathic tendencies and a penchant for murder as a child. To save his son from being locked up in an institution or receiving the death sentence, Harry decided he would help use Dexter's Dark Passenger to rid the world of serial killers, or murderers who have slipped through the cracks in the justice system. However, these rules that Harry created still weighed on his conscience, with the police officer ending up taking his own life after seeing Dexter in action.

Rule one: don't get caught

Harry teaches Dexter how to escape suspicion

First of all, the most important rule in RightThe Harry Code of r is “don't get caught.” If Dexter was caught, he would face prison or execution, with Harry even taking a young Dexter to see an execution firsthand as a precautionary measure. Most of the other rules in Harry's Code are used to ensure that the first rule is followed.

Dexter frequently reiterates that the first and second rules of Harry Morgan's code are the most important. There are several more specific rules, such as “leave no trace or evidence”, “Fake emotions and normalcy”, and “never make a scene”, which are steps to ensure that the first rule of Harry Morgan's code is followed. It is also this rule that shows how much Harry cares about his son. Of all the rules and advice he left for Dexter, most were there to ensure that Dexter's Dark Passenger didn't land him in prison (or, worse, the death sentence).

The first rule of Harry Morgan's code includes the importance of mixing socially and maintaining a “normal” appearance, faking his emotions and leaving no evidence or traces of his crimes (like with Dexter's drug M99/ketamine). Leaving no evidence also means never making a scene because you get emotional or have clouded judgment – The first rule of Harry Morgan's code ensures that Dexter can continue killing as long as the future Butcher of Bay Harbor follows a clinical and methodical approach.

Rule two: never kill an innocent person

How Harry Keeps the World Safe from Dexter

If the rule “don’t get caught” was how Harry Morgan kept Dexter safe from the law, “don’t kill innocents” was how he kept the world safe from Dexter. After he discovered his son's dark impulses and murderous urges, Harry made it clear that he would not help Dexter become a traditional serial killer. Instead, he would help his son use his Dark Passenger as a force for good. This will only be possible if Dexter is incredibly selective with his victims and – most importantly – never kills innocent people.

The rest of the rules in Harry Morgan's code that are not related to the first rule are those that keep Dexter's Dark Passenger controlled and operating under a moral guideline. Harry's Code is strict in how Dexter can kill and who he can take as victims. After never getting caught, the most important rule in DexterHarry's Code is to never kill an innocent person.

However, this rule can sometimes be broken to adhere to rule number one, such as Dexter the main character must avoid being discovered at all times. This means that there were times when Dexter had to take the life of an innocent person to avoid being exposed – and from his teachings and flashback scenes, it's likely that Harry knew this would be the case.

Rule three: Targets must be murderers who have escaped the justice system

Harry was specific about the criminals Dexter killed

Training Dexter to be an assassin who killed other assassins ended up psychologically breaking Harry, a lifelong police officer. However, although the guilt of creating such a violent presence capable of operating outside the law led Dexter's father to take his own life, Harry Morgan's Code is still clear about the legal system. Harry was clear with Dexter: he cannot choose victims who have not yet been caught by the competent authorities.

This rule is the next step in Harry Morgan's code after not killing innocents. It's not enough for Dexter to target people he suspects are murderers or criminals – they must have been charged first and considered dangerous by authorities. Harry Morgan's code helps Dexter correct the errors of the legal system, not act as a moral judge. If Dexter is looking for a victim, he must also be certain that the person he kills is a murderer, which involves intense research on the part of Michael C. Hall's character. In conjunction with this important rule, Harry's Code states that Dexter's victims must be murderers who have escaped the justice system or slipped through its cracks.

Rule Four: Killing must serve a purpose

The Spiritual Core of Harry Morgan's Code

Of all of Harry's rules in Dexter, “killing must serve a purpose,” which is the most important in many ways. It's this rule that captures the reason why Harry decides to help Dexter control his Dark Passenger, beyond simply being a protective father. As a police officer, Harry is against murder. However, he also knows that the legal system allows many murderers to go free. It was this knowledge that led Harry to create the code – it is a set of guidelines that harnesses Dexter's impulses for a purpose and gives them reason.

This was so important to Harry Morgan that he made sure it specifically stated that it was part of the code. Dexter should only kill when there is a clear and solid reason. Knowing that Dexter's desire to kill has no inherent motivation for his bloodlust, Harry Morgan created the rule that all of his deaths must have a purpose, otherwise it is “simply murder.” Dexter's killings must have been for the purpose of preventing the deaths of innocents or “balancing the books”, as their murders cannot be motivated strictly by revenge.

Rule five: no preventive deaths

Dexter shouldn't make the first move

Of all the rules Harry Morgan left for Dexter (which are not methods of keeping his identity hidden), “no preemptive deaths” is one of the most specific. Harry knew that Dexter was smart enough to identify other serial killers before obtaining enough evidence and that in many cases he would be correct. This is why Harry ensured that Dexter would never make a mistake by including the rule that prevents any preemptive killing.

It's not enough for Dexter to rely on his knowledge of serial killer psychology to identify a potential target – he must have proof. Furthermore, Dexter should also never act to prevent crimes before they happen. Node Dexter In the episode “Seeing Red”, the 10th episode of season 10, Dexter mentions that Harry has been very clear about this particular rule, and has also been honest in saying that he sometimes finds breaking it tempting. With the prequel series Dexter: Original Sin Coming in December, viewers are likely to get a much more detailed version of Harry Morgan's code and the origins of each rule.