A plot by literary standards is merely "everything acts for the greater narrative." That's it. Characters, scenes, relationships, everything is enslaved to the narrative. It's optional. You don't need a plot to save the world in an RP. The characters don't have to act within a narrative. Everything I've done has repeatedly, and demonstrable proven to me, over and over, that a greater narrative only enslaves characters. It railroads them. It forces them to do as you please, instead of doing what is natural.