you know how in video games you have two types of characters, baseless NPCs that only have one or two sets of dialogue and then you have the story relevant NPCs that you talk to in order to move the story along and typically follow the player around and have a whole character development with their involvement? NPC games refer to the first ones, the ones you'd find in their house that just say stuff like "Boy the weather has been pretty good today lately, huh?" every time you talk to them. It's like a psuedo version of time stop but without actually stopping time.
But to answer your question, yes, it's pretty much walk around a map and find the female NPCs and just fuck them where they stand. There has yet to be an attempt at a full sized RPG game with npc fucking mechanics which honestly would be a huge undertaking but would probably be received pretty well.
