Guessing is bad. Reading is better.
But no, the Emulator currently uses BOTH - rules and variables (and some hard-coded stuff still I am sure). Rules is relatively new (a year or so I think?) and things are moved from coded/DB settings to Rules as dev time permits. Plus, adding many new customizable options which make each emulator server unique.
Read the changelog.txt that is inside the source package (the one on the website is truncated)