Games and Mods link
Like all games and other software that you run on your computer, you should only run a Ren'Py game if you trust the creator and everyone involved in getting the game to you. Malicious software, including games written in Ren'Py, can perform arbitrarily harmful actions on your computer, and can even send information elsewhere.
This includes mods that involve changing a game or Ren'Py's source code - if you don't trust the creator of the mod and everyone that brought it to you, you should not apply the mod.
Save and Persistent Files link
Ren'Py save files, including the
persistent file, are created using
the Python pickle format. This file format is powerful enough that it
should be treated like software - if a malicious person can get you to
load a file they created, they can run arbitrary code on your computer.
It's best to treat save and persistent files as if the files contained software, and only load them if you trust the creator of the file, and everyone that brought it to you.
Save and persistent files are not designed to be shared between players, and so those files may contain information about you and your computer. We recommend that you do not share save and persistent files with other users.