Continuity mistake: In Chapter 19, Wade describes the small efficiency apartment he has moved into, which used to be an average hotel room. He says at one point that the room "was basically a cube, about ten meters long on each side." A ten-meter cube is actually a really big room - that's over 32 feet on each side, including ceiling height. Then, just to confirm that this is indeed a mistake, later in the same chapter he refers to "my tiny one-room apartment."
Continuity mistake: Dumbledore tells Harry at the end that Lord Voldemort is the last remaining ancestor of Salazar Slytherin. But ancestors are in the past - he means Voldemort is the last descendant of Salazar Slytherin. Not a mistake Dumbledore would have made. (Corrected in later printings.)
Continuity mistake: Before Harry and Hermione go back in time, it mentions that Buckbeak is tied to a tree. But when they go back in time, Buckbeak is tied to a fence.
Continuity mistake: During Priori Incantatem, Voldemort's victims come out in reverse order. However, James comes out before Lily. He should come out last, because he was killed before Lily. (Corrected in later versions of the book).
Continuity mistake: How can Ron and Lavender be in a 'prominent corner' of the Common Room when in Harry Potter and the Philosopher's Stone, it says it is a circular room?
Continuity mistake: Harry buys the book "One Thousand Magical Herbs and Fungi", but later, the title changes to "One Hundred Magical Herbs and Fungi".
Continuity mistake: Eddie's broken arm changes around, sometimes it's the left arm that's broken, sometimes it's the right.
Continuity mistake: The pickup truck with the painting of the Gypsy woman and the unicorn in Chapter 6 changes into a VW microbus in Chapter 18.
Continuity mistake: At the beginning of the book Meggie mourns leaving the farmhouse she has lived in for just under a year, but at the end of the book she suddenly remembers having lived there for the past several years.
Continuity mistake: Greg says that Hero Points are printed on sheets of 10 (page 52), but on the next page, Erick is holding a sheet of 12 Hero Points. On the page after that, the Hero Points are back to a sheet of 10.
Continuity mistake: In the chapter entitled Smooth Criminal, Reed is asked by the Billing's Girls to steal a physics test and that she has 15 minutes to do it. Early in the chapter she states that after glancing at her watch she had already wasted 4 minutes but at the end of the chapter she states that she wished she'd had time to put on a watch as she had no idea how much time was elapsing.
Continuity mistake: When Aladdin is battling Jafar, he is shown holding a sword. On the first page of this, the part of the hand guard on the sword that is on the sharp side of the sword is curled up and the back side is curled down. But the next page with the sword shows this reversed.
Continuity mistake: When Clay and Tom are threatening to break into the hotel, Tom says "I'm going to grab a kerbstone and smash the glass", but Clay says "A curbstone?" Since they both say it, there should be no spelling error.
Continuity mistake: On Page 69 (Part One: Blood Sport) the Owner of the Kelly Fruit Company is called Hubert, but on page 217 (Part Three: Wreckage), his name changes to Henry.
Continuity mistake: At the start of Part 6, the men let Percy out of the closet. They take the tape off his mouth and he starts to rub his lips, then lowers his hand to speak. Problem is he's still in the straight-jacket at this point.
Continuity mistake: In Part 3, Chapter 33, two news reporters come to see Annie and interview her about the missing policeman. She walks out with a shotgun full of "double-ought buck", fires a warning shot, and then when she re-enters the house she magically has a rifle, not a shotgun.
Continuity mistake: During Robert and Sophie's escape from the Louvre they head toward the Gare Saint-Lazare when they realise the American embassy has been cut off by police. However, in the very next chapter they arrive at the Gare du Nord, a completely different station.
Continuity mistake: The Longsword Fighter that landed in Ascendant Justice's hangar bay is repeatedly referred to as a Pelican on pages 75, 93, 95 and more.
Continuity mistake: This is seen over two books: Artemis Fowl and Artemis Fowl: The Eternity Code. In Artemis Fowl, Chapter 2, Artemis cracked his knuckles when he was trying to decode the fairy Book. However, in Artemis Fowl: The Eternity Code, Chapter 1, Jon Spiro cracked his knuckles, and it is stated that Artemis detests that habit.
Continuity mistake: In chapter 18 Scudder visits Dr. Nadler at his Manhattan office but in chapter 32 we hear that Nadler was in Martha's Vineyard at the time.