|Savage Worlds Mars|
My first attempt was using Savage Worlds and the Mars sourcebook, primarily because of Snizith's blog, Savage Barsoom, had already done some of the work. It didn't take me long though, to realize that I didn't know Savage Worlds well enough to feel comfortable in creating such a big supplement as J&J, so I abandoned that system.
My next port of call was DC Adventures, which is based on the Mutants &Masterminds 3e rule set. I had already done some work for the system as a freelancer, so I knew it quite well. The system easily adapts to the swashbuckling cinematic feel of Burroughs' Barsoom while being grainy enough to support a huge plethora of characters and creatures of differing ability.
So, with that decision made, I sat down and began making notes on how I wanted to set out the supplement..