Many years ago now I was told that we needed a way to turn a series of lights on and off for a custom bit of hardware. The hardware ran a Unix-like system so I decided that a daemon would be a good fit for the use case. I do not know what has become of my daemon of light but I do know whomever uses it must call the “summon” function to daemonize the process
If you don’t mind using a different system GURPS has a free 32 page lite version of the system that gives you all the basics
https://archive.org/details/pdf-gurps-lite-fourth-edition