One of DC Comics’ premiere superheroes, at least where Hal Jordan as Green Lantern is concerned, he and his partners have saved the world and the universe more times than anyone can count. Of course, we’re not just talking about Hal, Kyle Rayner, John Stewart, or Guy Gardner. Though they are among some of the best and most popular Green Lanterns in the cosmos, they and those they serve with aren’t your typical superheroes. Rather, they’re an intergalactic police force that ensures the universe runs smoothly. Every Green Lantern is picked due because of their ability to overcome fear and demonstrate incredible willpower.

The Green Lanterns were founded by the Guardians of the Universe, a race of nearly immortal beings who were trying to find a way to protect the stars from evil. After a few missteps, the Guardians chose to form a peacekeeping force out of sentient and compassionate beings. However, giving anyone a Green Lantern power ring without any safeguards would be foolish. And so the Guardians established a set of rules all Green Lanterns had to abide by. Some of these rules could be found in the Book of Oa, while others were created later. We’re looking at 15 different rules every Green Lantern has to follow.

15 ALWAYS OBEY THE GUARDIANS

Within most groups, especially those that are military related, there is a chain of command that must be followed. This ensures that everyone does his or her job and a sense of order is established. For a fighting unit to work, everyone has to be willing to listen and do as they’re told. The refusal to follow the orders of your superiors can result in the loss of life, including your own and your team members. Your superiors are your superiors for a reason; they have greater experience and oftentimes know the right call to make. Now multiply that by about a factor of a million and you get close to appreciating how things work in the Green Lantern Corps.

The Guardians of the Universe, the little blue alien humanoids responsible for creating the Green Lantern Corps, might not be the most emotional bunch, but they know how to get things done. Sure, sometimes their inaction proves hazardous, spurring Lanterns like Hal Jordan to go rogue and take charge of a situation that they know needs dealing with. Even so, Hal and company is technically in the wrong whenever they do this, as it undermines the institution of the Green Lantern Corps. The rules were set up for a reason, Hal!

14 DEFEND ALL LIFE

It’s not a secret by any stretch of the imagination, but the primary purpose of a Green Lantern is to protect life in all its many forms and varieties. However, this need to defend the stars from evildoers everywhere began eons before the likes of Hal Jordan even donned Abin Sur’s Power Ring.

Before the Guardians of the Universe were the designated Guardians of the Universe, they were a species of alien known as the Maltusians. After an experiment by one of their own went awry, a group of Maltusians decided to dedicate the rest of their existence to containing evil and creating an orderly universe. In their first attempt to eradicate evil, the Guardians created the Manhunters, a legion of robotic sentinels. The machines eventually malfunctioned; believing the only want to create order was to destroy all life. Horrified with their creations, after the Guardians did away with the Manhunters, they decided to star up a new force of soliders that would consist of living beings with free will and who had strong morals; a sort of celestial knights. Like the knights in Arthurian legends, the Green Lanterns have a strong responsibility to protect and cherish all life they come across, even if it might initially appear foreign or hostile.

13 DON'T INTERFERE WITH A PLANET'S CULTURE

When a Green Lantern flies about from galaxy to galaxy and planet to planet, they tend to come across a bunch of stuff that many would consider weird. However, the job of a Green Lantern is not to judge and adjust a culture or world to what they deem appropriate, but rather offer protection if anyone is in trouble. Altering the natural course of a planet is not only frowned upon, but the Guardians have a very clear rule about it: don’t do it. In other forms of media, this is known as the Prime Directive. It’s a conceptual law that primarily applies to civilizations that are below a certain level of technological, cultural, and scientific development.

The rule, as imposed by the Guardians and others, is supposed to prevent a couple things. The first of which is that this disallows Green Lanterns from using their superior powers and intellect from imposing their own values. Furthermore, tampering with a culture, even if one’s intentions are benign, can have disastrous effects, as their natural development might be altered. That said, a Green Lantern is allowed to interfere if interference has already been done; the Green Lanterns will then try and minimize whatever damage has occurred. Be that as it may, that still hasn’t stopped a hothead like Hal Jordan from flying into a world, overthrowing a tyrannical government or two, and then going on his merry way. Still, though his intentions are noble, such action disrupts the natural order.

12 DON'T USE YOUR POWER SELFISHLY

This here is a big one and it’s a rule that’s most often abused by Green Lanterns and those aspiring to be Green Lanterns or wield a Power Ring. A Green Lantern Power Ring is limited only by the imagination and willpower of the wearer. In the wrong hands this could mean a great many things. It’s not even that that a Power Ring could be dangerous if wielded by a madman, but just as a rule of thumb, the Ring and the wielder are instructed not to mess with fate. One of the best examples of this is when Cyborg Superman and Mongul destroyed Hal Jordan’s hometown Coast City. Completely distraught, Hal tried to resurrect his city and the people who had died, with his Power Ring.

The results were mixed, as everyone and everything was green, but Hal had essentially succeeded. Yet the reality he created didn’t last and fell apart. Though the Guardians then warned him not to use his power for his own purposes, Hal ignored them. Going on a full bender, he slaughtered his fellow Green Lanterns, took their Rings, and head to Oa to acquire more power so he could bring back his loved ones permanently. As you’d expect, things didn’t go well, which is why the Guardians have this rule implemented in the first place.

11 LEAVE BEHIND WORLDLY ATTACHMENTS

Many of who are chosen to become Green Lanterns dedicate themselves completely to the cause. A good number of Lanterns have nowhere else to go and that’s just fine with them. On the other hand, you have Green Lanterns like Hal Jordan, Kyle Rayner, Guy Garnder, etc. who herald from Earth and all have things they want to get back to. For Guy, it’s a cool glass of beer, for Kyle it’s his art, and for Hal it’s his family.

Yet there was a time when the Guardians forbade Hal to interact with his homeworld, demanding he commit completely to being a Green Lantern and nothing else. It was a test to see whether he had what it took to remain an interstellar cop, since he’d been on the outs with the Green Lantern Corps and the Guardians. And so, the Guardians demanded Hal leave behind all worldly attachments. Failure to do so would result in Hal getting kicked out of the Corps. Hal argued against the rule, stating that keeping him from home was doing a disservice to him and his ability to perform his job. He needed an emotional tether, something to fight for and come home to, else risk losing all motivation; it could happen to any Green Lantern. The Guardians saw logic in his argument and denounced this short-lived law.

10 COOPERATE

A team is only as strong and effective as its weakest link. A fighting unit like the Green Lantern Corps cannot operate at full strength unless everyone is on the same page, Lanterns and Guardians alike. If any one individual thinks that they know best and refuse to work side-by-side with their fellow Corpsmen, that only offers an invitation to disaster. It’s one of the many reasons why the Guardians of the Universe instituted the following law, stating that a Green Lantern must show full cooperation with both the Corps and the Guardians.

At its most basic level, failure to cooperate with the Corps means that the unit might not be at full strength in a time of crisis. Time and again we see some Green Lanterns, especially those from Earth like Hal Jordan, saying "to heck with the rules" as he fails to cooperate and decides to do his own thing. While this typically works out for him, it’s only because he’s a main character and is safeguarded by a little thing called plot armor. Even so, when Hal leaves his fellow Lanterns behind, it shows a refusal to cooperate with orders the Guardians have given, leaving the Green Lantern Corps with one of their mightiest members missing half the time.

9 GIVE PRIORITY TO THE GREATER THREAT

As a member of an intergalactic peacekeeping police force, being a Green Lantern means one is going to constantly not only get thrust into dangerous situations, but judgment calls are going to have to be made. If you’ve heard the adage that “the needs of the many outweigh the needs of the few”, then you have a pretty perfect example of the mental balancing act a Green Lantern must adhere to. Deciding what threat requires your attention over another threat is not an easy matter. How do you determine whether to save a building that’s about to explode that’s also full of your friends and family, or a planet you’ve never heard of that you have no emotional investment in that’s on the verge of annihilation?

If you only have time to do one or the other, then you’re in something of a no-win situation. It’s a difficult line to navigate. While your instinct might be to save your loved ones, that would be against the rules. After all, a planet full of billions is worth more than a handful of people, at least according to a pragmatist. Even Green Lanterns like Hal Jordan have found themselves in similar situations, and while it pains them, when the Guardians order them leave loved ones to their fate, all in the name of the greater good, there’s no choice but to obey.

8 SHOW RESTRAINT OF FORCE

Wielding the most powerful weapon in the universe can occasionally get to one’s head. That’s why the Guardians of the Universe were insightful enough to implement the following rule: show a sense of restraint when performing your Green Lantern duties. See, in the heat of battle, or even if you’re just taken unaware by some thug with a regular ‘ol laser gun, it’s easy to get a bit carried away in the the moment and strike, out of surprise. Either way, when you’re hitting someone with pure will power, they’re typically going to be on the losing side of that argument.

Realizing this, the Guardians designed Power Rings so that they couldn’t commit lethal force. Killing gets in the way of the rule stating that Green Lanterns are supposed to defend life, and not extinguish it. For years, no matter their opponent, Green Lanterns could not kill anyone. Granted, they could probably use their Ring to pick up a battle cruiser and throw it at somebody’s head, but the energy of the Ring itself couldn’t end anyone’s life. Later, during the "Sinestro Corps War", Green Lanterns were allowed to exercise lethal force. Since then, it’s still an option, but they have to ask for permission for the ability to get unlocked.

7 OBEY THE LOCAL AUTHORITY

If you’re a Green Lantern then that probably means you have the ability to crack a planet in half. Yet just because you’re incredibly powerful, doesn’t give you the right to enforce your will on the locals of another world. In fact, even if you’re doing police work on an alien world, the local authorities are still the ones in charge. This is a way of demonstrating respect and making sure a Green Lantern doesn’t overstep their bounds. Every planet has their own set of rules, and while certain laws might appear strange or even barbaric at first glance, it’s not for an outsider to come in and tell a civilization that’s been around for thousands of years how to get something done.

If a world doesn’t have local law enforcement, then a Green Lantern must still pay respect to whatever authority is present. This all ties back to several pre-established laws, like not interfering with a planet’s culture, not using one’s powers to enforce one’s will (something the villain Sinestro has done on more than one occasion), and even showing a restraint of force in case you come across peoples who are unfamiliar with Green Lanterns and might even prove aggressive.

6 RECHARGE YOUR POWER RING EVERY 24 HOURS

Being a Green Lantern involves a lot more than just flying around space and hitting bad guys with green boxing gloves. Like any military or peacekeeping profession, you have to take care of your tools so that they take care of you. In this case, a Green Lantern must look after their Power Ring. They have to ensure it remains charged so that it doesn’t go out while you’re flying through the vacuum of space or involved in an intense battle. It’s easy to forget such a detail. Even worse then forgetting, is not being told the requirements of charging your ring or that it needs to be charged in the first place.

When Kyle Rayner first became a Green Lantern, he was the only one left and there was no one to instruct him or guide the young hero in his adventures. Upon first donning the Ring, Rayner didn’t know that it needed to be charged every 24 hours, else it completely run out of battery and be left ineffective until the next time it was recharged. Not only did Rayner figure this out the hard way, but he also learned, like every Green Lantern has learned before him, that in order to charge up the ring, one must spout the Green Lantern oath loud and clear.

5 OVERCOME FEAR

Serving as a Green Lantern requires fortitude and dedication. You can’t afford the luxury of being afraid when you’re trying to protect the universe. At it’s most basic level, a Green Lantern regularly deal with fighting monsters and malevolent aliens. Fear leads to a lack of concentration and improper focus, which in turn paves the way for you to be ineffective when you’re ring-slinging. The more complicated side of fear is that it can lead individuals to commit rash and malicious actions, as seen when Hal Jordan became Parallax. Because of this, instruction on fear is an important lesson that must be learned. There is the misconception that only those without fear are elected to be Green Lanterns. This is not the case. Rather, it’s okay for an individual chosen to have fear, but they are chosen because they possess the ability to overcome fear, and therein lay the difference.

However, not every Green Lantern is able to overcome fear. There are former Green Lanterns like Sinestro who turned away from will power and instead decided to dance with fear. Harnessing the emotion, Sinestro became the first Yellow Lantern and sought to instill order throughout the universe by utilizing fear as a weapon.

4 KEEP YOUR CONCENTRATION

A Green Lantern Power Ring isn’t referred to as “the Most Powerful Weapon In the Universe” for nothing. It’s a device with practically unlimited power. The Power Rings are capable of granting faster than light travel, teleportation, invisibility, force fields, energy blasts, and of course, the famous hard-light constructs. The power of the Rings themselves is limited only by a particular user’s willpower and imagination, the stronger the will, the most powerful the constructs. With a weapon fueled by the mind, a Green Lantern ought to be among the strongest mortal beings in the DC Universe. Shown capable of even creating Kryptonite that could weaken Superman, and functional machinery that could serve as a temporary organ replacement, the sky is the limit with a Green Lantern Ring. That said, a weapon is only as deadly as the person who wields it and their skill level.

If you’re a Green Lantern and you get distracted in the midst of battle, it often means the difference between life and death; a distraction could break your concentration and in turn weaken your defenses or attacks. Furthermore, while older comics demonstrated that a Power Ring couldn’t be removed without a user’s consent, recent years have retconned that so now if you’re not focused on your ring or the task at hand, an enemy can snatch it off your finger.

3 WORK ALONGSIDE THE YELLOW LANTERN CORPS

This might seem like an odd one, but not too long ago the Green Lantern Corps had mysteriously disappeared. No one in the universe knew where the fabled intergalactic police force had vanished. This left a tremendous vacuum of power as the cosmos started to become like the Wild West, where, in the absence of some kind of police force, there was no one to uphold any kind of order or law. Sinestro, the leader of the Yellow Lanterns, builds a planet-size fear engine and used it to administer his brand of order. When the Green Lanterns return, not only do they unite against Sinestro, but also many of Siniestro’s fellow Yellow Lanterns left him, having begun to feel that he was doing more harm than good.

After that was out of the way, John Stewart, the leader of the Green Lantern Corps, and Soranik Natu, the new leader of the Yellow Lanterns, make an agreement to put aside any lingering hostilities and work together. Every Green Lantern would have a Yellow Lantern as their partner. This union lasted longer than most anticipated, but eventually comes to pieces after a series of misunderstandings. Still, while the rule was implemented, both sides took the mandate very seriously.

2 UPHOLD THE HONOR OF THE CORPS

In establishments like the police, the Army, Navy, or you name it, there is a certain code of integrity that many try and adhere to. Fighting and dedicating yourself, all in the name of others, and doing it with honor, is of key importance. As for the Green Lantern Corps, you can imagine that acting as the police for the entire universe is one that requires everyone to be at top form. In order for planets among the cosmos to respect the Green Lantern Corps, the Green Lanterns must first respect themselves and always try and behave respectfully when in the line of duty. That is to say it doesn’t pay for Green Lanterns to go have drunken brawls in a bar on a far away planet (we’re looking at you, Guy Gardner).

If one Green Lantern looks bad, then every Green Lantern looks bad, and if every Green Lantern looks bad, then worlds stop giving Green Lanterns their trust. Without trust, it becomes difficult to do their job. Not to mention, just as important as anything else, no Green Lantern wants to bring shame to his fighting unit and friends. Being a Green Lantern is an honorable position and ought to be treated as such.

1 DON'T TAKE ACTION UNTIL SOMEONE'S A PROVEN THREAT

When is the right time to pull out your Green Lantern Power Ring and blast someone in the face? That’s the question, or at least the equivalent thereof, that all officers of the law have to face at some point, even if it’s interstellar law. Because of the tremendous power a Green Lantern wields, they are usually the top dog in a any fight. Their Power Rings give them a gigantic advantage, so it’s imperative to know the correct moment is to unleash that advantage. Many species that Green Lanterns face are not strong enough to prove a threat to the Lanterns themselves, and as the cops of the universe, the job of a Green Lantern is to diffuse a situation rather than let it get out of hand. Even if an alien appears like a threat, there is the mandate that a Green Lantern is not to take forceful action with his Power Ring until an individual has proven himself or herself to be a legitimate threat.

This also applies to moments when Green Lanterns have been outgunned. It’s imperative to know when to walk away and live to see another day, and knowing if it’s time to make a last stand. Written by the Guardians in the Book of Oa, it’s usually the responsibility of the Green Lantern Corps leader to ensure his colleagues don’t fire without his or her express order.