As of right now there isn't a selected theme. This is like the preparation phase for the actual jam (determine what tools you'll be using, meet up with teammates, get the base framework setup, outline characters/plot., get your assets in order, etc.). You can vote on a theme in the links section on the RPGM5 Concept Jam page, but the actual jam starts on the first. The link is also on the concept jam page but ill link it here too: https://itch.io/jam/rpg-mania-v