What could possibly turn Iron Man and Cap against each other in Captain America: Civil War? The latest Tumblr craze is the Captain America: Civil War meme, and it offers many explanations for why these two Avengers could end up going head-to-head.

We know almost nothing about how the Marvel Cinematic Universe will interpret the Civil War storyline in Captain America 3. Of course, in the comics the war is fought over the Superhero Registration Act. Iron Man is for, and Cap is against, but for now it’s unclear how much of this storyline will translate into Captain America: Civil War.

At the end of last year, Marvel President Kevin Feige said, “It’s not about the secret identity thing, as much as it is about, overall, who reports to who, and who can agree to oversight committee.” But Spider-Man also plays a crucial role in this fight in the comics, and — despite Marvel’s best efforts — he won’t be appearing in Civil War.

Related: Five reasons people think ‘Civil War’ won’t work (and why they’re wrong)

So how exactly will it all go down? Luckily, the internet (namely Tumblr) always has the answer. The meme is as follows: choose the smallest, most ridiculous argument the two could have, and use that as the basis for this superhero civil war. Hilarity ensues.

The best of the ‘Captain America: Civil War’ meme:

Some play into classic fandom debates…

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…and more recent Marvel fandom debates:

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Some are thanks to their antagonistic relationship:

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Then there is their weird joint history:

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And finally, perhaps the only real reason to go to war…

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What do you think will be the breaking point for Iron Man and Cap?

Unfortunately, we’ll have to wait for the real answer until Captain America: Civil War premieres on May 6, 2016.