>>718274987 (OP)
Make a MMO where all classes you can play as are -Trade- classes.
Merchants are jack-of-all trades and can manage the auction houses and buy and sell at credit.
Blacksmiths are heavy weapons users that can craft weapons in-game.
Herbalists have druidic powers and can create potions.
Hunters are the bow/xbow class and can process monsters for ingredients.
Enchanters are the in-game designated wizards and can enchant items and create runes.
And so on.