Continuity mistake: When Robin Williams and the cop are driving to the store in the cop car after the windshield was broken, neither of their hair is messed up and they can see clearly. (01:12:50)
Continuity mistake: In one of the closeups of Alan sitting in the car as it is crashing through the displays inside the Sir Savalot Store, the background, visible through the driver's side window, is of open fields, trees and blue sky. (01:13:00)
Continuity mistake: When the Aunt flags down the cop car, the cop has his seat belt on, as the plant starts coming in the car to grab him and the car. He jumps out of the car without ever undoing his seat belt. (01:14:45)
Continuity mistake: Carl's cop car has the licence plate "G2298" which is printed thinly on the licence plate. Then, when the vine wraps around his car, and bends it in two, the licence plate is now "CFJB95", printed very boldly on the plate. The words "POLICE 004" also differ, as does the bumper and the lights. Totally new car, methinks... (01:14:55)
Visible crew/equipment: Just before the monsoon, everyone is in the attic and Judy tells Sarah that she needs to roll a 12 to win. When it cuts to Peter, you can see his tail behind him, and the wire attached to the tail is visible, holding it up and swinging it about. (01:15:35)
Revealing mistake: During the monsoon scene, everyone is on a table trying to climb on the chandelier. Peter has been turned into a monkey, and his face is covered in hair and has the characterists of a monkeys face, yet in shots when they are on the table, like when the crocodile snaps at them on the table, just before Alan lifts Peter onto the chandelier, you can see the plain face of his stunt double, with no monkey features! Robin William's and Bonnie Hunt's doubles are rather obvious in these same shots too. (01:17:20)
Revealing mistake: During the monsoon scene, Sarah has both her feet aginst the jaws of the crocodile, and so Alan jumps from the chandelier, and dives into the water. As he dives into the water, watch Sarah's feet, and her left foot slips into the crocodiles mouth, and his upper jaw slams down on it! The crocodile has a row of sharp teeth on at the front of it's mouth, which come down onto her shoe. That would be painful, yet she doesn't scream/limp/complain. (01:17:55)
Visible crew/equipment: When the police car gets dragged off by the vines, there are wires visible attached to the boot of the car. (01:18:00)
Continuity mistake: During the scene when Alan is trapped in the quicksand, and the others are giving him items to hold onto, you can see behind him, to the viewers right of the blue chair in the background, a small stack of newspapers. But in later shots, such as after Peter runs out of the attic to go to the shed, and we then see Judy crawl over and grab the wooden music stand, to hit the spiders, the stack of newpapers has vanished, and a few other items change position, like the tennis racket. (01:20:55 - 01:23:00)
Revealing mistake: When Alan's face is stuck into the floorboards, after they had turned to quicksand, the boards assumingly go back to being hard and wooden, yet in shots of Alan talking you can see the boards bounce/wobble slightly, showing they are rubber. (01:21:45 - 01:22:45)
Continuity mistake: When Peter runs out of the attic to the woodshed to get the axe, to the left of the attic door is a large filing cabinet, with nothing in front of it or beside it. Yet later when Peter is swinging the axe at the spiders, and following shots, a green suitcase has appeared in front if it. (01:22:45 - 01:25:00)
Visible crew/equipment: In the scene with the big tarantulas, many times you can see the strings attached behind them, especially the one Peter swings the axe at. (01:24:35)
Deliberate mistake: When the house is splitting in two, the board game should have fallen long before it actually does. (01:25:25)
Continuity mistake: When the earthquake begins, the floorboards start to break in two, and Alan starts falling so Sarah holds onto him. Watch the small circular window in the wideshot. (the window that the mosquito flew out of earlier in the film) To the left of the circular window are some empty wooden beams, but no items. When it then cuts to a closeup of the window breaking in two, items have appeared on the beams, and there's a banjo hanging up etc. (01:25:30)
Continuity mistake: After Sarah and Alan have been embedded into the floor by the quicksand, she rolls the dice with her teeth onto the board that's been propped up on Alan's face. The next time we see the board, when Peter's fighting with the spiders, the board's completely flat on the floor, when Alan's head should be propping it up. There's no angle between the main board and the two halves that fold out, but they are bent downward in the previous shot. Also, after Alan moves the board, at first it's relatively perpendicular to his face. Then, a few shots later when the spiders are retreating because of the impending earthquake, the board's rotated 45 degrees and moved farther away. It wasn't moved by rumblings from the earthquake- this is before the ground actually begins to shake. (01:28:15)
Continuity mistake: When Judy is fighting off the spiders, the floor breaks and a purple plant comes out of the floor and shoots her in the neck. You can see the barbs, but in the next shot when her brother starts running toward her, they magically disappear, and in the next shot they appear again. (01:30:30)
Other mistake: In the scene where Robin Williams tells Sarah that she needs a 12 to win, she rolls a 3. The next time she rolls, Robin tells her she needs a 7 to win.
Continuity mistake: When Alan is trapped on the floor, and the game is placed over his head, Sarah rolls the dice which fall on the lower left corner. When the angle changes they've moved further to the right.
Continuity mistake: When Alan confronts the lion with a knife, the blade is either facing flat or sideways depending on the angle.
Revealing mistake: When Alan's merged with the floor and the first huge spider shows up, there's a thin wire coming out of its rear to make the animatronic move.
Chosen answer: Most games don't need you to roll the exact number of spaces left in order for someone to win. By rolling twelve he gets to move his ten spaces & has won. I'm assuming it's easier for him to roll two sixes than anything else.