Would you rather have

[MrBehemoth]

I voted story, but I ought to explain why.

There's a huge difference between writing and narrative. Narrative is the story you tell and how you tell it. You tell narrative through all aspects of the game/mod/CS: art, environments, sound (including music), events, puzzles, mechanics, UI, not just through the writing and voice over. Since we're talking about mods, you've got limited control of the mechanics and UI, so first and foremost your story should fit these. Then begin to tell the story by what the player sees, feels and experiences.

Don't separate it out. Thomas Grip wrote a really good article on this: http://frictionalgames.blogspot.se/2014/...roach.html