MagiRogue is a 2D grid-based roguelike game with a deep magic system, complex combat mechanics, and an aura system with eldritch fauna. Players can build and customize their own magic tower and interact with NPCs through a coven of wizards. Players can progress from an apprentice to an archmage or choose to abandon magic and live as a common person
http://howtomakeanrpg.com/a/how-to-make-an-rpg-stats.html
https://www.reddit.com/r/gamedev/comments/4fucve/how_do_developers_create_and_refine_their_rpg/
https://gamedev.net/forums/topic/683035-designing-a-stateffect-system-for-an-rpg/5314973/
https://www.reddit.com/r/gamedesign/comments/3puffc/how_do_you_design_a_rpg_attribute_system_where/
https://www.redblobgames.com/articles/probability/damage-rolls.html