Crazy campaign idea: Paranoia meets the Masquerade meets generic fantasy.

[jdrakeh]

When was the last time you played Paranoia?

I admit that it has been a while, but I know that when I did play it wasn't completely unordered, unmanageable, chaos.

 

[Dannyalcatraz]

Some might say you weren't playing it right.

 

[Wolfwood2]

I think it would work fine as a campaign setting, however the main reason for that is this:

The players would never know. They would just assume that, even though noone THEY ever fight is actually human, that it's just because they're adventurers. Your great secret would be protected by the assumptions of the typical D&D campaign: that the PCs are unique special butterflies fighting unusual threats.

Well now it stops being unworkable and becomes pointless. The players are your only audience. If they never know about it, then who is the concept supposed to entertain? Is the DM just going to go giggle to himself after every session when the players complain, "Your plots are getting really repetitive. Seems like every little village is monsters in disguise!"

 

[Saeviomagy]

Well now it stops being unworkable and becomes pointless. The players are your only audience. If they never know about it, then who is the concept supposed to entertain? Is the DM just going to go giggle to himself after every session when the players complain, "Your plots are getting really repetitive. Seems like every little village is monsters in disguise!"

Well, naturally there's eventually going to be a big reveal, at which point your campaign world may or may not fall apart. Simply pitch that point for when you want your campaign to transition to something else.

Leading up to that, your job is to plan out how that reveal comes about. The fact that every villain seems to be a monster in disguise is a sort of side-hint.