10 Times The MCU Broke Its Own Rules

9. The Arc Reactor Can Power Iron Man...Except When It Can't - Iron Man 3

Tony Stark's (Robert Downey Jr.) arc reactor serves as the power source for his Iron Man armour - as well as initially powering the electromagnet which kept shrapnel away from his heart - so why, exactly, doesn't this work for his Mark 42 armour in Iron Man 3?

Instead, when the armour runs low on power, Stark is forced to break into Harley's (Ty Simpkins) garage and hook it up to a car battery, allowing it to (slowly) charge.

While the real answer is "because plot," and the reaching answer is that the Mark 42 only has a single, specific power source (its battery), is it in any way reasonable to accept that mega-genius Tony Stark would really design an Iron Man suit that couldn't be charged by his arc reactor?

In a series where Tony Stark can ass-pull the means to time travel after an evening of committed thought, are we really supposed to believe that he couldn't use the arc reactor to get his suit operational?

It's ultimately just an excuse to give audiences a de-powered kitchen sink Tony Stark for a while, even if it requires checking Stark's signature resourcefulness at the door.