Board Thread:Naruto Discussions/@comment-34436445-20180616210453/@comment-734582-20180616214230

Soloking itachi15 wrote: It is said that sharingan can copy any jutsu except kekkai genkai I think this is confusingly worded. The Sharingan can gain insight on any jutsu, and through that insight copy it. This works for any jutsu. However, the user must still be physically able to perform that jutsu. Madara copied all of Hashirama's wood jutsu, but he couldn't actually perform those jutsu until he got Wood Release. Similarly, something like the 8 gates can only be achieved through tremendous training, and so if the user doesn't train themselves it cannot be copied.

The Rinnegan doesn't break this rule. It grants insight in a different way, seemingly a sort of base understanding of chakra itself. This means the user can easily manipulate chakra (e.g. elemental transformations) and easily create new jutsu. However, the user must still be physically capable of doing so.