Gday! I believe the ruleset (also posted in the AI mega thread) published at NESDEV sets up a frame for rules that may be applied here (or, pretty much any other similar place).
With regards to percentages:
"Projects that are primarily AI-generated are banned unless they provide meaningful utility to the community.
- If the human’s role in the project was primarily prompting AI rather than directly making a majority of the actual assets or code, do not post about it here.
- If a major component, such as art, music, or code, was made by you, the project is allowed even if some other components are entirely AI-made. However, you must focus on the parts you made. We also strongly recommend collaborating with another developer on the parts you can’t do instead of using AI.
- If you have something like an AI-written tool, script, or disassembly that is sufficiently different from anything that already exists and would make others more productive, that is allowed. Just please don’t come here to show off your vibe-coded version of something we already have and works well.