Can I just say Sword Noir? No?
Back when I was playing d20, my favourite house rule wasn’t one of my own, it was Kenneth S. Hood’s Grim ‘N’ Gritty Combat Rules. Originally, these were available for free, but they got so popular, Mr. Hood (or someone representing him) put them up for purchase. That makes total sense to me.
I wrote a review of the free version back in my free e-zine days. You can find that here.
#RPGaDAY2015 is the brainchild of game designer Dave Chapman. Basically, each day in August there is a question about RPGs.