Revealing mistake: Jack and Elizabeth are marooned on the island, and he goes down the stairs to the cache of rum. From below, he lifts his right arm up holding a bottle of rum and we see the pirate brand. It's a CG brand, and in this shot, the pirate brand is crooked and off to the side. It doesn't look the same as the close-up when Norrington lifts Jack's sleeve in Port Royal, and it's not because of camera angle. Jack's sun and sparrow tattoo isn't where it's supposed to be either. At this point in filming, this 'tattoo' on his arm is not a real tattoo, it is only applied for specific shots, and make-up didn't apply it for this shot. (This has nothing to do with Depp's real tattoo that he supposedly got later, after filming.) (01:36:15)
Revealing mistake: Will walks down the stairs, after the coach leaves and the cottage to the left of the Governor's mansion isn't seen at all. In this close-up, the Governor's mansion behind Will is only a facade built at Marineland. They only built the facade for the main house, not the two servants' cottages on both sides of the mansion. In the next wide shot, both cottages and the mansion seen, are miniatures used in a CG composite on the hill. Given the proximity of the (miniature) cottages at both sides of the house in the wide shot, the left cottage should've been seen in the close-up, but obviously couldn't because the cottages weren't built. Fuller view of the wide shot in deleted scenes. (00:08:45)
Revealing mistake: Jack says, "Or you could surrender." Soon after, Barbossa smacks Jack in the face and we can see Jack's wig and red forehead scarf coming off his head, as he's going down. You can clearly see Tony Angelotti's (Depp's stunt double) forehead, sideburns and hairline in the right hand corner of the screen. (The shot right after this one is Jack running with his arms waving.) (01:57:15)
Revealing mistake: When Will opens the door to the blacksmith shop, behind him to his right is the sign for the silversmith across the courtyard. When the Royal Navy bursts in to capture Jack, behind the men is the same sign for the silversmith. The wall and silversmith sign in both of these background composites differ with each other in position, angle and dimension in relation to the door and the people standing in the doorway in both shots. This has nothing to do with the camera angle of the two shots. (00:21:55 - 00:26:50)
Revealing mistake: When Jack sees Will run toward the Aztec chest, he quickly slices his palm and parries with Barbossa. In the shot facing Barbossa, Jack strikes the sword out of Barbossa's hand, then as Barbossa spins around his right hand is empty, and we hear the sword falling in the distance. However, when Barbossa says, "Ten years you carry that pistol..." Barbossa is still miraculously holding his sword - the sword tip is moving at the bottom of the screen, as he speaks. (More of the sword is visible on VHS.) (02:00:45)
Revealing mistake: In the close-up of Jack as he swims to get his gun, etc, his left sleeve is pushed up and it's very obvious that he's wearing something with short sleeves under his white shirt. This isn't part of his white shirt. He has nothing on under his white shirt at any other time. (The underwater close-up of Depp was filmed in a tank at Long Beach along with the close-ups rescuing Elizabeth earlier.) (01:34:50)
Revealing mistake: In the scene where Jack and Will have just taken the Interceptor and the Dauntless is coming about, the men on the row boat get caught in its path. A second after the men abandon ship, you see the boat get destroyed. If you look closely at the forward wake of the ship, the boat is too far away to be destroyed by the front of the ship. And since the boat initially goes down when it's struck, it can't be the keel of the ship, since that would send it up. (00:48:05)
Revealing mistake: During the sword fight in the blacksmith's shop, Will pulls a blade out of the fire. While fighting Jack, the heated blade sparks when their two swords clash. When Will blocks a hit from Jack, the impact is far BELOW the red/orange hot section of Will's sword, yet it sparks right at that spot. It also makes a kind of sound like electricity crackling. A heated blade would not make this noise, nor would it send out embers or sparks where it is not heated. Only the tip is heated, however the whole blade has an electrical current running through it, mentioned in another mistake. (00:24:15)
Revealing mistake: Before Interceptor's explosion, in the close-up it's very apparent that it's not the real Interceptor. Some examples are, no rigging at the stern-most mast, at the railing there are no belaying pins with or without all the lines hanging from them, there are no cleats with or without lines and at least two of the swiveling mounts at the stern for the swivel cannons aren't there. (01:30:40)
Revealing mistake: During the attack on Port Royal, Will crosses his axe (left hand) and sword (right hand) overhead to block a pirate's blow and then proceeds to slice that pirate across his abdomen. Yet in the previous shot, in which another pirate with a cap stabs a man who is leaning against a stone wall, we see Will in the background on the left of the screen, having stabbed that pirate in the abdomen already. Obviously cut and the takes were edited out of sequence. (00:31:20)
Revealing mistake: When Will opens the door to the blacksmith shop, on his immediate left outside, there is a stone wall with a plaque on it. That same plaque can be seen hanging high up over a doorway across the courtyard from the blacksmith's shop, when Jack goes into the shop earlier. The wall and plaque were added later, to that shot of Will. The plaque should not be able to be seen so closely, at that angle and distance, in the shot of Will opening the door. (00:20:40 - 00:21:55)
Revealing mistake: When Elizabeth falls down from the cliff, with her hat and scarf falling over her, you can see it is definitely not Keira Knightley, as the stuntperson's face is perfectly visible. (00:15:05)
Revealing mistake: When the gallows, in the Fort's courtyard, blows up, just before the huge explosion, four of the platform legs can be seen exploding in the same place, at the same time. A horse and rider pass by in the wide shot, another platform leg, the arm of the gallows and the actual platform explode in sync. Also, in the next close-up we see where the nearest leg of the platform has been cut to help facilitate the explosions impact. (00:31:25)
Revealing mistake: The clasp closure on the medallion's chain is NOT the sort that just comes apart when yanked on, evident in the many close-ups of the clasp throughout the film. Yet there are a number of scenes in which the chain is just pulled and it comes off easily: Elizabeth pulls it off aboard the Pearl, to barter with; Barbossa pulls it off, during her blood ritual; Elizabeth pulls it off to give to Will, aboard the Interceptor... The chain was secured to her neck with sellotape, in order for it to come off quickly for the shots. (01:12:15 - 01:19:28)
Revealing mistake: When Jack rescues an unconscious Elizabeth, as he reaches to lift her, his wet white shirt is translucent. From just above the elbow we can see the pink of his skin showing through the sleeves, but above that it's very apparent that he is wearing another garment under the white shirt. Yet when he's on the dock, there is no other garment under his shirt, which is still translucent enough to see the two tattoos on each of his shoulders. (00:16:00)
Revealing mistake: When Jack and Elizabeth are marooned on the island, Jack wants to know why the rum is gone. Elizabeth sits down in front of Jack, and as he stands behind her, he puts his fists up to his chin in frustration. His right forearm does not have the sun and sparrow tattoo showing, although part of it should be. The entire tattoo would not be hidden under his sleeve, makeup simply did not apply it for this shot. (01:39:20)
Revealing mistake: In the close-up of Barbossa cutting Elizabeth's hand, we see as the blade goes across Elizabeth's palm, leaving an obvious thin red line where the blade sliced, but not leaving blood on the blade as it slices. The creases in her palm are also unaffected by the 'cut' that's being made. Yet when Barbossa holds the blade up to his face, the blade now has a good amount of blood on both sides. (01:12:00)
Revealing mistake: Jack slips aboard Interceptor and Murtogg and Mullroy run aboard and confront him. In Jack's close-up he begins to say, "Well then, I confess." The next shot is of Murtogg and Mullroy, while Jack continues to say, "It is my intention," and as he says, "to commandeer one of these ships..." there is a shot from behind Mullroy's right shoulder. As Jack speaks, Mullroy turns his head to the right and quickly glances peripherally to his side at the camera, so as not to bump into the steadicam at his elbow. Angus is not looking at anything else. (00:13:50)
Revealing mistake: When Pintel and Ragetti are below deck with the cannon and hit with forks and other utensils from the Interceptor's canons, Pintel's eyes are seen. The yellow contact lenses that Lee Arenberg wears as Pintel are seen in this and other shots during the movie. (01:25:30)
Revealing mistake: Johnny Depp's and Orlando Bloom's stunt doubles, Tony Angelotti (Jack) and Mark Aaron Wagner (Will), not only fight each other's 'alter ego' as well as other pirates and soldiers, they also duel directly with each other in the blacksmith shop in many shots. They are also too obvious in the scenes on Isla de Muerta, and during the rescue of Jack from the gallows, as they run and fight the Marines. There are notable differences between the two Jacks and two Wills within all the shots, throughout the film. (00:24:45 - 02:07:00)
Answer: The curse needs the blood of everybody who took a coin from the chest. All the other pirates have already contributed so, as the movie opens, the only blood needed is Will's, substituting for his father. During the finale of the movie, Jack takes a coin from the chest, adding himself to the curse, so his blood is now required as well as Will's.
Tailkinker ★
But I didn't see any blood on the coins, and none of the pirates cut themselves, even before Will became part of the mix.
Yes, the other pirates did cut themselves before Will came into it, off-screen. The lack of blood on the coins can simply be explained as most of it dripping to the bottom of the chest, it being washed away by storms blown into the cave, or by the fact that they didn't drop that much blood on it in the first place.
When they had Elizabeth they believed she was Bill Turner's daughter, but they all thought the curse had failed, none of them had cut themselves so it makes zero sense.
They had been collecting back the coins for years. During that time they repaid their own blood. All they needed was the last coin and the blood of Bill Turner to break the spell.
lionhead