Autarch has finally started their kickstarter for their Lairs & Encounters Book for Adventurer Conquer King System.
It is usable with most OSR clones and neo -clones.
The production of all of the ACK books to date have been stellar and I have quickly become a fan of the system.
I had used some ACK references in my previous S&W campaign.
I am plaining on running my next campaign using solely ACK.