That being said, the main gripe I have is the charactarization of the Mandarin. In the comics upon which the characters are based, the Mandarin is one of Iron Man's primary villains. He first saw print in Tales of Suspense #50 in 1964. His main weapons are 10 alien artifacts that he wears as rings on each of his fingers. The rings allow him to project energy off varying types, including fire, ice, wind, electricity, physical and mental force, among others. In the film, however, this is far from the way he's portrayed.
In the film, the Mandarin is portrayed as a terrorist, which is largely his modus operandi in the comics as well, however, in the comics, he's a quasi-mystic, portraying the alien origin of the rings as magic, knowing that they are, in fact, science. the alien origin of the rings, however, is not even hinted at in the film, nor are "The Ten Rings" mentioned, above and beyond being the name of the organization the Mandarin leads.
I have to preface what follows by stating that I am not, currently, a reader of Marvel comics in general, or Iron Man specifically, so much of my information here is 2nd hand. That being said, I believe most of the story elements in this film are pulled from more recent Iron Man and/or Marvel comics, specifically the Extremis procedure.
Not knowing much about the storyline in the comics, in the film, Extremis is an experimental procedure that allows the human body to heal itself after traumatic, sometimes even catastrophic injuries. It was developed by Maya Hansen, played by Rebecca Hall, who is a biochemical engineer and one-time lover of Tony Stark. Maya now works for Advanced Idea Mechanics, or AIM, the product of scientist Aldrich Killian, (Guy Pierce), a one-time fan of Tony Stark who, when we first meet him, suffers from a noticeable injury, but by his 2nd appearance is fully healed.
It turns out that Maya and Killian, through AIM, have made great strides in developing Extremis and are looking to enlist Stark in developing it further by asking Pepper Potts to try to get Stark Industries to ally itself with AIM. Pepper refuses citing the possibility of Extremis becoming weaponized. Those fears are realized when Happy Hogan is caught in the epicenter of an explosion at Graumann's Chinese Theatre, for which the Mandarin claims credit.
Stark vows vengeance against the Mandarin for putting Happy in a coma and the action in the story ramps up. Stark's home is destroyed as are many of the displayed armors. Surviving the attack at his home, Stark, beaten and exhausted, rockets, in damaged armor, to Tennessee, site of a previous Mandarin-type explosion not linked to the Mandarin. During his investigation in Tennessee, he befriends a young boy named Harley Keener, played by Ty Simpkins, who aids Stark in his investigation, giving him many key pieces of information about the small Tennessee town in which Harley lives.
The Mandarin continues to wreak havoc on the U.S. and the President, played by William Sadler, by breaking in to live television broadcasts and making threatening pronouncements to and about more upcoming threats against the country. The Iron Patriot, the former War Machine, Lt. Col. James Rhodes, is tasked to find the broadcast site the Mandarin uses to issue his threats and is captured by one the Extremis agents.
Harley aids Stark in repairing his damaged armor as well as Jarvis, the armor's artificial intelligence operating system, voiced by Paul Bettany. Jarvis leads Stark to a mansion owned by Killian where he meets the Mandarin, who it turns out is just an actor. Killian, it turns out, is not a pawn but the mastermind behind the Mandarin menace and the weaponization of the Extremis procedure.
It's at this point I renew my distaste of the treatment of the Mandarin as a villain in this movie. The Mandarin is not a petty functionary, but a menace in and of himself. He is one of the most powerful threats in the Marvel Universe and to see him portrayed as a figurehead, lowered to the level of a drug-addicted soccer hooligan is, to a comics reader like me, very aggravating.
If i were to give Iron Man 3 a grade, I'd give it 3.5 out of 5. It loses a point because of the Mandarin. I'm sorry, it's just hard to get my head around.