Plot hole: The Man goes completely trigger happy shooting all the walls all around his house, trying to kill Fool, Leroy, and Roach at different points. The police come in and don't notice anything wrong. What about the bullet holes all over the place?

Continuity: In the opening scene when Ruby is laying the tarot cards down for Fool, the cards that she lays down changes position in the following shots, most noticeably the Devil card.

Continuity: When Fool turns the TV around to look at it, in the cellar, he is wearing a plaster on his thumb. In the next shot when he runs away up the stairs, it has gone, and never returns.

Revealing: When the Woman is trying to attack Alice with the huge butchers knife, in one shot you can see it bend and wobble a little bit, revealing that it was fake and rubber.

Continuity: When the Man tells Prince to shut the fuck up, the amount of blood on his chin changes between shots.

Continuity: In one scene where Fool goes back into the house to get Alice, he takes a fire-poker from the fire place. As he walks through the house, you can see the poker is intact. After he strikes "Daddy" you see the poker break. In the next shot, the poker is back, unbroken.

Plot hole: Since Roach has been able to elude Daddy for so long, why couldn't he take a few sticks of the dynamite in the house, rig up the front door blowing it open, and set all of the People under the stairs free?

Continuity: When Fool walks down the stairs, he picks up Spencer's lighter and pad, then gets scared and runs back upstairs. As he runs, between shots the items he holds swaps hands.

Continuity: When Fool hides behind the cat-flap style vent, at the end of the hallway, The Man comes down with his gun. The items behind the vent change position (eg. the cloths, bones, etc.)

Continuity: When the third Person from Under the Stairs bursts out (from the wall) the Woman is flinching in the corner, pressing up against the wall. As she does she breaks the brown wooden panel in the wall behind her, splitting it in two. In the next shot the wall is back intact.

Continuity: When Alice talks to Fool in the bathroom about not speaking, hearing or seeing any evil, a tear rolls down her cheek but in the next shot it's gone.

Continuity: When Leroy breaks into the back door of the house, the door has nothing on it, yet in the next shot from inside the house as they enter, the glass panels on the door are covered in ivy.

Continuity: When Roach writes 'Alice' in the white wall, in the first shot he writes it neatly. In the next shot the writing is very messy, then neat again in the next shot.

Revealing: When Fool fall off of the edge of the bathtub it is quite obviously a taller stunt double used instead.

Revealing: When the Woman is attacked by the People from under the Stairs, it quite clear that it is in actual fact a stunt double.

Revealing: When Fool is in the bathroom and the father pokes his head through the door (after firing a rifle at it) turns to Fool who smashes a concrete slab on his head. The blood mark in on the father's right temple, but he was clearly hit in the middle.

Factual error: When Fool calls the police from a coin phone, he puts the coin into the phone, then calls 911. Given that 911 is a free call we should hear the sound of the coin being returned immediately after it was dialed, but we don't.

Continuity: When all of the People from Under the Stairs attack the Woman in the kitchen (as she tries to stab Alice) one of the people climbs out of one of the cabinets twice between shots.

Continuity: When Alice is pushed into the blood to mop it up, the bucket of water sits beside the dining room rug. In the next shot it is suddenly in the middle of the blood with Alice.

Continuity: When Fool tips Alice's dolls onto her bed, in the next shot the pile is positioned differently.