Most cave systems I've been in are zero visibility. All you could see was the underground river reflecting the light from the glow worms, and the glow worms themselves on the cavern roof. And that was only a tiny part of the system. The light went in for maybe ten metres, then it was all black. I agree about you needing to see things, though. Maybe it should be more the level of light when you're in an airplane, and it's taking off, and they but all lights but this ones glowing down from the wall on... If that makes sense to anyone.

I'm all for this idea. It'd also be cool if the guards did something at the castle... Maybe if there was an added doorway, and the guards forgot to guard it at night, and there was something in there. I don't know what, just as long as it isn't a free hat or hat store. And guards could start to guard a few more; like, maybe a room leading to the bedrooms would be guarded heavier.

This idea would be awesome to see, especially if you could slowly see it getting darker, and all the NPCs hurrying around and doing things. That last bit might be a little hard though.

Ohhh, and you could use it for a new Hallowe'en quest. There's a guy, and if you stay in his house after sundown, he barricades you in to 'stop the Baddies coming in,' and then, as he just laughs nervously in a corner like a maniac, you need to get out... Or something. Maybe counsel him. Hurrah.