Best Resources for people designing their own systems

What are the resources you find useful in designing your own systems? I will post a couple that I find helpful.

Here are some links to reddit forums I found useful:

And here is a twitter account from a guy who does computer game level design that has a ton of stuff that is very applicable for TTRPGs. Here is an example: Implicit information vs. explicit information:

For example: here


Here’s another video game series, Game Maker’s Toolkit by Mark Brown, with lots of TTRPG application. My video gaming son got me hooked.

The BRP Systems Reference Document (SRD), from Chaosium, contains guidelines for publishing content under the BRP Open-Gaming License.

I really enjoy Call of Cthulhu 7e This scales well on how heroic or superhero or normal you want your characters.