Hi Friends:
I don’t know how is your spanish, But I share this article about “mechanical matter” I just get on a page about RPGs in my country. Enjoy it if you can!
http://www.roleros.cl/2015/06/mecanicas-de-juego-que-valgan-la-pena.html#gpluscomments
PS: John Harper , I have quoted you!
My Spanish is quite weak, but Google helped me out with a rough translation. Looks good!