Sticking feathers up your butt, does not make you a chicken
1) Games are what they are. (About as close to a zen koan as you are likely to see in gaming.)
2) Games are not what they are not
3) Games are the sum of their parts1) Games are what they are.
If you have systems for fighting, you have a game that is at least partly about fighting
DnD is a fighting game. As evidenced by all the rules about fighting.
2) Games are not what they are not
If you do not have a system for something, the game is not about that.
DnD is not about internal conflict, because there are no rules about internal conflict.
Sidebar: So, you can't have a Murder Mystery in a DnD adventure?
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The answer is you can have it, but it is not really the game, it frames the game. (oh this will get more confusing still)
We are playing DnD we find a dead body. We search it, find goblin semen and go off to kill goblins. We are detectives right? Well, no. The GM knew the next adventure was to kill goblins, so he led you to it. If you had failed that roll it would have been something else. This is active participatory framing. The end was decided already.
As a quick aside:
Is this railroading? Po-tay-toe Po-tah-toe. We define railroading as the GM deciding the End point and How you will arrive there. But it is close enough that some might consider it so. I advise you not to play DnD then.
Is this false choice railroading? (This is when the PCs are presented with two choices but both are the same.) No, there were manyways of figuring out that goblins did it. The GM let you solve the problem the way you wanted to.
Is this fiat? Oh god yes. You made up the adventure and the in game reason the PCs would go. Yes it is fiat.
Politics, Dramatic Stories, Murder Mysteries. These can all frame DnD games.
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3) Games are the sum of their parts