Even though RPGs can vary wildly, there are still plenty of common themes they frequently share—features that a player expects out of your game.
This one goes without saying. Every RPG—and I do mean every RPG—has these basic concepts.
Statistics, or stats, are the numbers that govern all combat in the game. While the actual stats can vary, it's common to have stats such as max health, max MP, strength, defense, and more.
As players progress through the game, these stats also improve. Their character becomes better in a variety of ways, reaching maximum potential at (or near) the end of the game. The exact way in which this is handled can vary, but most games implement experience points or ...