2b. For new players: helpful basics
Most of this section is definitions to set up basic contexts for the game. If you’re completely new to the game or need a complete refresh, I recommend reading through this whole 2b section; DN has a lot of little things you need to know that truly mount up, there’s always something you could be missing.
I also recommend going through the in-game tutorial (seperate from the few prompts you get after the first cutscene of the game), it will teach you some basic actions that will be helpful to commit to memory. If you started in Prairie Town, you can take the tutorial by speaking to Mayor Harold.

If you started in Mana Ridge, you can take the tutorial by speaking to your class’ Master: Master Cleric Leonard for Cleric, Master Sorceress Cynthia for Sorceress, Academic Station for Academic, and Eltia Justitia for Lancea.
