I just thought that it would be possible to duplicate Pokemon in X and Y. They are offering digital downloads of the game, where you should be able to just copy the game/save onto your computer and then after trading you can roll it back to a previous save point. Another thing may potentially be is that it could be ripped from the game card and then placed back on after a trade. The only thing that wouldn't be possible though is sending these save files to others due to the encription, but rolling back your own save should be possible. One thing is that would Nintendo predict this may happen? They could easily counter it by storing the save file on the 3DS itself for Digital download games rather than the SD card and for the game card to be able to be played on multiple systems with the same save they could probably store it on both the game card and 3ds system, the save file having a unique identifier code which if that save file has been played before on that 3ds, it would compare the save files and either will be overwritten with the newest save file. One thing with that though is there could still be a potential to duping using multiple 3ds's, so the only solution for that would have to be that the save file needs to be stored on the cart a different way to all other games, possibly something like Animal Crossing which can block out Gateway. EDIT: http://gbatemp.net/threads/question-about-id-checks-with-3ds-and-new-leaf-save-files.349216/ Just read this thread, makes me a bit sad that they don't just save the digital download save on the internal memory, because it would suck to have your sd corrupted an lose your save.