You could see Captain America: Civil War because Spider-Man is adorable and Chris Evans has lots of muscles. But if you truly want to *get* it, you're going to need to do your research.
So, which movies should you watch ahead of Marvel's latest offering? Obviously, Captain America: The First Avenger and The Winter Soldier. Also, Avengers and Avengers: Age of Ultron, Iron Mans 1, 2, and 3, Ant-Man and The Incredible Hulk. If you don't have an entire weekend to marathon what amounts to the entire Marvel Cinematic Universe thus far (minus the Thor movies), we have a handy cheat sheet.
Civil War truly builds off everything that has come before it -- which is one reason this superhero v. superhero set-up works so much better than, say, Batman v Superman -- but the below primer should be sufficient.
OK, but What Movies Do I Really Need to Watch? If you have time to watch two movies pre-Civil War, let them be The Winter Soldier and Age of Ultron, despite what you may or may not have thought about Age of Ultron. Cap 2 sets up the dynamic between Captain America (Chris Evans) and Winter Soldier (Sebastian Stan) and Steve Roger's distrust of the government. AoU sets up Tony Stark's (Robert Downey Jr.) ongoing guilt complex.
Bonus: Watch this scene from the original Captain America. It will pay off in all of the feels.
What's the Deal With The Winter Soldier Again? Is He a Bad Guy? That depends who you ask, and is a major question mark in Civil War. But what you need to remember is that the Winter Soldier is actually Bucky Barnes, Roger's WWII buddy from the 1940s who was presumed dead after falling from a train. Turns out, Bucky was actually brainwashed by HYDRA and turned into a metal-armed assassin.
All of which is to say: If you ask Cap, he would say that Bucky wasn't in control of his own brain, so all of the terrible things he has done -- murder, mayhem, blah blah -- wasn't entirely his fault. But we discovered in the post-credits scenes of Cap 2 and Ant-Man that Bucky is starting to remember who he is.
There's Like, a Million People in This. Who Else Do I Need to Remember? Most faces will be familiar -- Hawkeye (Jeremy Renner) and War Machine (Don Cheadle), Black Widow (Scarlett Johansson) and Falcon (Anthony Mackie) -- but Vision (Paul Bettany), who is J.A.R.V.I.S. as a human, basically, and Scarlet Witch (Elizabeth Olsen), the result of HYDRA experimentations, are new to the team.
You know Peggy Carter -- as in, Agent Carter -- but now we know Agent 13 (Emily VanCamp), who was tasked with spying on Cap in Winter Soldier. Her real name is Sharon Carter. Yes, they're related -- you'll soon find out how. There's also Brock Rumlow (Frank Grillo), a S.H.I.E.L.D. agent turned low-level baddie who "got a building dropped on him" and is back with a vengeance as Crossbones.
You may not remember Thaddeus "Thunderbolt" Ross (William Hurt) from the red-headed stepchild of the MCU, The Incredible Hulk -- that's the one with Edward Norton. He was the general who was in charge of the military project that turned Bruce Banner into the Hulk. Now, he's Secretary of State.
The Starks? What's Going on There? Howard Stark (Dominic Cooper and then, at some point in his life, he turns into John Slattery -- it's the latter version here) is an inventor and businessman who worked with Agent Carter and the Strategic Scientific Reserve, before becoming a founding member of S.H.I.E.L.D. Howard and Maria Stark (Hope Davis) died in an "apparent" "car" "accident," with Tony inheriting Stark Industries.
Tony has a cornucopia of daddy issues.
And Why Is Everyone Fighting Again? It's all more or less explained in Civil War, but the gist of it is that, while the Avengers have saved the world on numerous occasions -- from evil aliens in Manhattan, from evil elves in London, from evil robots in Sokovia (you're going to hear the name "Sokovia" a looooot) -- there have been casualties. And the time has come to account for them.
More importantly, #TeamCap and #TeamIronMan go back to Winter Soldier and AoU, so, you know, watch them. Cap doesn't trust authority after HYDRA infiltrated every level of S.H.I.E.L.D., while Tony feels incredible remorse after creating the aforementioned robot that tried to destroy humanity.
What About Everything That's Happening on Agents of S.H.I.E.L.D.? Literally, it does not matter.
ET was on the set of Captain America: Civil War and found out how the cast hazed the new heroes and who got challenged to a dance-off. Find out in the video below.