Revealing mistake: When the Emperor's generals are introduced at the start of the film, pay attention to Sheeva's lower arms. If you look closely, her lower arms are added digitally and don't quite blend with the actress, nor do they 100% match her motion. (Especially her lower-right arm, which is on the left hand side of the screen. You can see it "clipping" with the background plate. At one point, it even briefly looks like it's floating behind her for a moment instead of being attached to her).
Revealing mistake: Jax and Sonya jumping away from the explosion when Cyrax self-destructs is just comical. The lighting on their bodies doesn't match the lighting in the background, revealing they were just filmed on a green-screen, and the background makes no sense whatsoever. The background is a blurry still image that doesn't have the same color-temperature as the exterior of the base seen earlier, with an obvious stock-explosion effect added over top of it that doesn't blend properly into the scene.
Continuity mistake: When Cyrax's "tattoo" flees his body, it rips a small hole in the metal of his shoulder. A few shots later, when we see the hole again to see the countdown clock, suddenly it's much bigger.
Revealing mistake: During the Jax vs Cyrax fight, at one point Jax gets knocked down to his knee, and then Cyrax kicks him, causing him to fly upwards and backwards and roll over the top of the metal gurney. Except you can see plain as day that Cyrax's kick completely misses Jax. He kicks his leg about two feet in front of Jax's head.
Revealing mistake: When Sonya is facing the "extermination squad" while Jax fights Cyrax, watch closely. At one point, a ninja clad all in black does a jump-kick, which knocks Sonya back. Except if you look closely, he doesn't actually kick her. (It's really obvious when the camera cuts to a side-view and you can see he doesn't have his leg extended.) But they still add in a kicking sound and have Sonya react as though she's been kicked.
Revealing mistake: During the Scorpion vs Sub-Zero fight, after the ice-bridge collapses, when Sub-Zero jumps down to the lower level of the stone bridge to face his foe, you can see the floor beneath him ungulate as he lands, revealing there's a pad beneath the snow.
Continuity mistake: During the Cyrax vs Jax fight, at one point Jax gets knocked to the floor and says "Yo, I take it this ain't something we can talk about?" If you watch, when the camera cuts from a wideshot of him landing to the closeup of him on the floor saying his line, he's suddenly in a completely different spot on the floor and the debris behind him is totally different.
Revealing mistake: Cyras appears, who launches two spherical bombs that attach to the walls and explode. Watch very closely. There is a low angle shot pointed towards a doorway right after they explode, and you can see the set wall visible shake for a brief instant from the pyrotechnics. It can be hard to catch, but once you see it, it's very obvious.
Continuity mistake: During the Liu Kang vs Baraka fight, at one point, two more Barakas swing down on chains. Liu kicks them off the chains, and they simply disappear for the rest of the scene. They didn't fall into the firepits, as you can hear them hit the ground, nor would the fall have killed them, as they aren't high off the ground. They simply... disappear.
Revealing mistake: During the Scorpion VS Sub-Zero fight, at one point, Scorpion kicks Sub-Zero and he almost falls into a lava pit, falling and wedging himself next to a stone pillar. (It's the bit where Liu has to jump across to save him.) When he hits the stone pillar, it wobbles like it's made of styrofoam, revealing it's not really stone.
Chosen answer: The films never address this but in the games Scorpion is an undead revenant and can't really be killed in a conventional sense.
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