The Marvel Cinematic Universe technically began when Tony Stark used a pile of scraps to become an armored superhero in 2008's Iron Man, but it wasn't until Earth's Mightiest Heroes first assembled four years later in Avengers that it truly felt like Marvel was building towards something spectacular. Since that epic initial crossover, we've seen several of our favorite comic book heroes team up on multiple occasions to take down some of the biggest threats imaginable and become so hooked on the franchise that we count the days until each next installment.
Now that Tony Stark sacrificed his own life to take down Thanos in Avengers: Endgame and Steve Rogers chose to use time travel to live out his life with his soulmate Peggy Carter and handed the mantle of Captain America over to his friend Sam Wilson, the fate of the Avengers is up in the air. While we know that the MCU and a number of the heroes we've grown to love so much over the past decade of films will continue fighting the good fight, it's still uncertain whether or not the MCU will ever give fans another Avengers team-up.
Viewers are understandably distraught over the possibility that Endgame will the last major crossover event, but it's hard to deny that after fighting the likes of Loki, Ultron, Thanos and even each other, our beloved protagonists deserve a bit of a break from world-ending adversaries. Being one of Earth's Mightiest Heroes is exceptionally hard, as Avengers have a long list of rules they have to follow at all times if they wish to stay on the team. It's not as easy as throwing on a costume and jumping into battle! Here are Avengers: 15 Rules The Team Has To Follow (And 10 They Always Break).
25 HAS TO FOLLOW: USE THEIR POWERS AND GIFTS FOR GOOD
The first rule that the Avengers have to follow is pretty straight-forward and obvious, but that doesn't mean it's easy. Every member of Earth's Mightiest Heroes is expected to solely use their superhuman powers or special gifts for good.
What separates Marvel's heroes from their villains is their refusal to utilize their talents for selfish gain. As Peter Parker explained to Tony in Civil War, since he wasn't an athlete before he got his enhanced speed, strength and stamina, it wouldn't be fair to use those talents to excel in sports at school. Instead, he uses them to help others as Spider-Man. All of the Avengers need to be that selfless, and accept that with great power comes great responsibility to do good.
24 HAS TO FOLLOW: COME UP WITH COOL SUPERHERO NAMES
Not every superhero needs to have a secret identity, but every member of the Avengers needs to have a cool code name. No villain would be afraid of powerless individuals who solely refer to themselves as Clint and Natasha, but Hawkeye and Black Widow sound far more formidable and intimidating.
The only exception to this in the Marvel Cinematic Universe is Doctor Strange, but it's likely just because the Sorcerer Supreme's name sounds heroic as it is. When Stephen introduced himself to Peter in Infinity War, the teenager assumed "Doctor Strange" was his "made-up" name and, in turn, introduced himself as Spider-Man.
23 ALWAYS BREAK: PUT THE NEEDS OF THE MANY ABOVE PERSONAL NEEDS
Every member of the Avengers has people they care about, but when they're forced to choose between their loved ones and the lives of countless innocents, heroes are expected to put the needs of the many above the needs of the few no matter how difficult that may be. Earth's Mightiest seem to struggle with that rule, though, and a lot of people have suffered as a result.
Scarlet Witch refused to destroy the Infinity Stone on Vision's forehead until it was too late, even though she knew Thanos needed it to wipe out billions of innocents. And when the Mad Titan threatened Nebula, Gamora brought him right to the Soul Stone to save her sister.
22 HAS TO FOLLOW: SAVE INNOCENT LIVES
Some common heroes might just use their superpowers to protect the people they care about or people in their schools or hometowns, but since the Avengers are considered to be Earth's Mightiest Heroes, members are expected to do much more than that. They're expected to save all innocent lives, even if they don't know the people they're saving.
Captain America has repeatedly shown over the past decade of films that he's willing to put his life on the line just to save one innocent person, and all of the Avengers are supposed to be willing to do the same.
21 HAS TO FOLLOW: WAIT FOR THE GOVERNMENT'S APPROVAL
In Avengers: Age of Ultron, Earth's Mightiest defeated Tony Stark's villainous robotic creation in Sokovia and prevented him from turning the city into a meteor that would wipe out all of mankind. Unfortunately, they couldn't stop his AI army from ending the lives of numerous Sokovian civilians.
The team's failure led to the creation of the Sokovia Accords, a set of legal documents designed to regulate the activities of enhanced individuals. The Accords required the Avengers to get government approval before each mission, turning control of the team over to General "Thunderbolt" Ross.
20 ALWAYS BREAK: DON'T ALTER TIMELINES DURING TIME TRAVEL
Scott Lang's experience in the Quantum Realm encouraged Tony Stark and Bruce Banner to figure out how to go back in time and retrieve the Infinity Stones from the past, so the heroes could assemble their own Infinity Gauntlet and snap billions of lives back into existence. Their objective was simple, but their mission wasn't easy to pull off.
The Avengers had to recover the Stones without messing up timelines and creating alternate universes. Unfortunately, they broke that important rule several times. There's now a timeline where Loki escaped at the end of Avengers with the Tesseract, one where the Guardians don't exist because past Gamora is now in the present, and one where Steve Rogers married and grew old with Peggy Carter.
19 HAS TO FOLLOW: VENTURE INTO SPACE WHEN THE MISSION REQUIRES
Just because they're known as "Earth's" Mightiest doesn't mean the Avengers get to just stay on their own planet all the time. When a villain threatens to destroy or conquer the entire universe, everyone on the Avengers' roster is expected to journey into space to fight against them.
When Nebula and Rocket told the Avengers where they could find Thanos, it didn't matter than none of them received any sort of astronaut training from NASA. They all got onto the Guardians of the Galaxy's ship and flew across the galaxy to get another shot at the Mad Titan.
18 HAS TO FOLLOW: CONSTANTLY UPDATE THEIR UNIFORMS
Members of the Avengers can't just go into battle wearing comfortable athletic clothes—they have to wear uniforms that will protect their bodies from whatever threats or dangers they might encounter.
Our favorite heroes rarely wear the same thing two Marvel Cinematic Universe installments in a row, because the more they fight, the more they realize their uniforms need little tweaks here and there for added safety, comfort and utility. Iron Man has updated his suit more times than we can count, and in trailers for Far From Home, viewers can see that Spider-Man will be testing out several new uniforms in his next solo adventure that will each likely serve a different function.
17 ALWAYS BREAK: DON'T MESS AROUND WITH THE LAWS OF NATURE
Villains tend to use their power, brilliant minds or influence to try to take over the world and reshape it in their own image. Several members of the Avengers are smart enough or powerful enough to play god if they want to, but they aren't allowed to do so.
Tony broke this rule in Age of Ultron when he messed with technology he didn't fully understand and accidentally created a robotic supervillain. Doctor Strange also messed with the laws of nature when he trapped Dormammu in an endless time loop against his mentor Mordo's repeated warnings not to do so. Both heroes had good intentions, but that doesn't excuse their potentially catastrophic actions.
16 HAS TO FOLLOW: PARTY WITH EACH OTHER AFTER BIG WINS
The Avengers are all expected to fight hard, and when they win, they're expected to play hard, too. Nothing brings a team together like a good post-battle victory party!
After they defeated Loki in the Battle of Manhattan, Earth's Mightiest all gathered together for some celebratory shawarma. When they teamed up again to recover Loki's staff from HYDRA, they celebrated their second win with a party at the Avengers Tower. Everyone drank, swapped war stories, and took turns trying to lift Thor's hammer Mjolnir. It was a great bonding experience, and helped them become a more unified unit.
15 ALWAYS BREAK: CAPTURE, BUT DON'T TERMINATE
Comic book fans have argued for decades about whether or not heroes should be able to terminate their more dangerous adversaries. Some think that Captain America and Superman are in the right for refusing to ever end lives no matter how evil, while others believe vigilantes like the Punisher are correct in thinking it's okay to take out irredeemable criminals.
The Avengers aren't ever supposed to eliminate their antagonists, but some of them break that rule pretty often. Thor had no problem "going for the head" against Thanos in Endgame, several Avengers eliminated the Mad Titan's Black Order in Infinity War, and Hulk's powerful punches undoubtedly wiped out some HYDRA soldiers in Age of Ultron.
14 HAS TO FOLLOW: SACRIFICE THEMSELVES FOR THE GREATER GOOD
When heroes join the Avengers, they're agreeing to do "whatever it takes" to save the world, even if that means sacrificing their own lives. It's not necessarily a rule that anyone on the team states out loud, but it's one that everyone accepts the moment they suit up alongside Earth's Mightiest.
Steve Rogers criticized Tony Stark in Avengers for not being willing to make the sacrifice play and jump on a grenade to save others, but Tony proved Cap wrong when he flew a missile into space to save all of Manhattan. Years later, he sacrificed his own life to eliminate Thanos with the new Infinity Gauntlet. Black Widow also sacrificed herself in Endgame so her best friend Clint could get the Soul Stone and bring back everyone Thanos snapped out of existence.
13 HAS TO FOLLOW: BE WILLING TO WORK WITH COMPLETE STRANGERS
Some heroes struggle to work well with others, but Avengers always have to be willing to team up with complete strangers. Since they often have the fate of the entire world—and sometimes even the entire universe—on their shoulders, they must remain flexible and learn how to fight alongside whoever volunteers to assist them.
Mere minutes after meeting Doctor Strange, Iron Man teamed up with him against Ebony Maw. Bucky and Rocket Raccoon worked great together in the Battle of Wakanda, despite not even knowing each other's names at the time. The final Endgame battle brought together countless heroes that had never teamed up before, but everyone worked as a unit because that was the only way they could defeat Thanos.
12 ALWAYS BREAK: TAKE EVERY MISSION SERIOUSLY
The Avengers only team up with each other for extremely important missions, so it's essential that every member is able to take those team missions seriously. There's simply no room for humor in battles against the likes of Ultron or the Mad Titan.
No one on the team seems completely capable of dialing down their sense of humor in serious moments, though. In fact, everyone—including more professional members like Captain America and Hawkeye—has made a joke or two during intense MCU fights over the years.
11 HAS TO FOLLOW: LEARN HOW TO USE A VARIETY OF WEAPONS
Every member of the Avengers has some sort of signature weapon that they prefer to use. Cap is rarely seen without his trusty vibranium shield, Hawkeye always comes equipped with a bow and some arrows, and Spider-Man uses his web shooters no matter what suit he's wearing. But they're all still expected to train with a variety of different weapons as well, just in case.
Clint and Natasha's mastery of various weapons constantly gives them an advantage against every adversary despite not having any superhuman powers, and Cap's experience working with Thor helped him instantly perfect usage of Mjolnir when he was deemed worthy in the fight against Thanos in Endgame.
10 ALWAYS BREAK: USE POLITE LANGUAGE
With the exception of teenager Peter Parker, every member of the MCU's Avengers is an adult and should be allowed to use adult language. However, Steve Rogers grew up in a different time and prefers to be more traditional and polite in his speech and mannerisms... and he expects his fellow Avengers to follow his lead.
When one of his teammates slipped out a swear word in Age of Ultron, Cap criticized them to watch their "language." Everyone simply laughed, and even Steve went on to utter a foul word or two in the following years.
9 HAS TO FOLLOW: TAKE ON LESSER VILLAINS SOLO
It's not easy to get all the Avengers together. Thor is often off-planet, Hawkeye tries his best to live a normal life with his secret family, Black Panther has a kingdom to run and Spider-Man has to worry about missing high school. That's why Earth's Mightiest Heroes only team up to fight villains they couldn't defeat on their own.
Villains like Yellowjacket, Vulture and Whiplash were formidable, but since their heroic adversaries proved capable of defeating them alone (or with the help of just one or two Avengers), they weren't deemed big enough threats to justify a full-fledged team-up.
8 ALWAYS BREAK: TEAM UP AGAINST WORLD-ENDING THREATS
Only major, potentially world-ending threats are important enough to justify an Avengers team-up, but sometimes, our beloved heroes fail to properly assemble to take on these villainous powerhouses.
Thor was so confident in his ability to take down the Dark Elf leader Malekith that he failed to ask any of his teammates for help against him, and it nearly led to the destruction of all nine realms. And since Civil War splintered the Avengers, they failed to provide a unified front against Thanos and his Black Order in Infinity War when the Mad Titan finally enacted his plan to assemble the Infinity Gauntlet.
7 HAS TO FOLLOW: CONTINUE FIGHTING AFTER THE FIGHT SEEMS LOST
Some people just give up when all hope seems lost, but the Avengers don't have the luxury of ever surrendering or accepting defeat. Everyone on the Avengers is expected to do "whatever it takes" to win, even after victory seems utterly impossible.
It would have been easy for those who survived Thanos' snap to just retire from being superheroes, but doing so would have been a disservice to all of the innocent lives that were lost. They were the only ones who could save the universe, and their continued effort helped them accomplish exactly that.
6 HAS TO FOLLOW: NEVER LEAVE A MAN BEHIND
While the Avengers are supposed to be willing to sacrifice their own lives for the greater good and to put the world's needs above their own, they're also expected to refuse to let a teammate go down unless it's the absolute only option. As Captain America stated when the Avengers discussed ending Vision's life to destroy the Mind Stone and foil Thanos' plan, "we don't trade lives."
This isn't necessarily the best rule, because as we learned from Tony and Natasha in Endgame, sometimes Avengers have to perish for the rest of the world to live. But since we hate losing one of our favorite heroes, it's a rule we're glad the team follows.
5 ALWAYS BREAK: DON'T DATE A FELLOW AVENGER
It's considered to be improper to date a co-worker, because doing so can blur the lines between one's professional and personal life. Avengers are not supposed to be with each other for that same reason, but that's a rule that Earth's Mightiest just can't help breaking.
Black Widow has flirted with most of the Avengers without creating any real drama, but when Star-Lord ruined the plan to strip Thanos of his Gauntlet on Titan upon learning that the Mad Titan eliminated his crush Gamora, viewers realized that it's probably not a good idea for heroes to get too emotionally invested in each other.
4 HAS TO FOLLOW: RECRUIT NEW MEMBERS
If the Avengers' roster still solely consisted of the original six members — Iron Man, Captain America, Hulk, Black Widow, Hawkeye, and Thor — there's no way they'd ever have been able to take down Ultron or Thanos. They constantly needed to recruit more and more superheroes to expand their team, and everyone was expected to play a part in that recruitment process.
Tony Stark helped bring War Machine and Spider-Man onto the team, and Cap recruited Sam Wilson, who went on to recruit Ant-Man. Thor brought in the Guardians of the Galaxy. Each new addition played an important role in the team's biggest victory in Endgame, and it's possible that if a single recruit wasn't on hand in the final battle against Thanos, the Mad Titan would have won again.
3 ALWAYS BREAK: KEEP THEIR EGOS IN CHECK
We love every single member of the Avengers, but it's impossible to deny that some of them have difficulties keeping their egos in check. Tony Stark is quick to brag about his status as a "genius billionaire playboy philanthropist," Thor and Hulk are always debating about which of them is truly the strongest Avenger, and nearly everyone attempted to lift Mjolnir to prove they were "worthy."
These petty quarrels have been funny to watch, but they're definitely problematic because the Avengers can't waste time on internal power struggles. Everyone on the team is on it for a reason, and they should all respect and value each other's contributions.
2 HAS TO FOLLOW: TRAIN TO STAY IN SHAPE AND BATTLE-READY
Black Widow is one of the world's greatest spies and Captain America may be Earth's best combatant, but that doesn't mean they don't constantly train to hone their skills and become better superheroes. During their limited off-time, Earth's Mightiest are expected to continue perfecting their special abilities, learning different fighting techniques, and staying in peak shape so they'll be ready if and when a new threat emerges.
Falcon and Scarlet Witch trained with Captain America at Avengers HQ at the end of Age of Ultron, and War Machine likely learned how to operate his suit through lessons with Iron Man. The Avengers may make being a superhero look easy, but that's just because they put in the work before each battle.
1 ALWAYS BREAK: DON'T FIGHT AGAINST EACH OTHER
The Avengers can only defeat their enemies if they work together as one cohesive unit, and that can't happen if they're fighting each other behind the scenes. They're expected to settle internal disputes in a civilized manner, but they've sadly failed to do that on several occasions.
Captain America and Iron Man nearly eliminated each other in Civil War, and their feud forced several other Avengers to square off against each other as well. Thor and Hulk have clashed on a few occasions, and mind-control/brainwashing caused Hawkeye, Hulk and Winter Soldier to fight their teammates.