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The big mainstream tabletop roleplaying games, don't really value roleplaying mechanically. In fact I would argue you could just try a different game, one that focuses on roleplaying foremost, and likely scratch your roleplaying itch in a more meaningful way. Sure they always include a rule zero, change the rules to fit your table, but I haven't personally seen someone actually detail how to make roleplaying a mechanic, a valuable part to how the game intrinsically functions.