The scene where Evan has no arms was achieved by using two shots: one with an empty bed, and one with Ashton Kutcher lying in the bed with green gloves on his hands (which were erased later).

伊万没有双臂的那场戏是由两组镜头合成的：一组镜头拍摄空的床，另一组镜头拍摄躺在床上、手臂戴着绿色手套(后期制作时被盖掉)的阿什顿·库彻。

youdao

So, in the darkness of an empty office building, Jason--whose idea of danger is "going to bed without brushing my teeth"--ends up going one-on-one against a trained killer.

FORBES: Correction Appended