I'll take the advice to heart, not to use them too soon. I feel however if they were put into a game then they are there for a reason. It's like an argument I have with the person that got me into DnD.
I read the Steven Erikson's book serise called "Malazan Books of the Fallen" that have gods placed all throughout the story. Faerun has about as many gods as the books. Somehow we got into a conversation if the group could ever possibly run into a god. He said no, what are the odds of you running into a god.
Now my perspective when your playing, your playing Hero's or people above average commoner in Dungeons and Dragons. I'd say your MORE likely to come into contact with one of them. Not right off the bat but as you go up in levels and are affecting the realm you'd either be stepping on some god toes or helping some. I don't see anything wrong with having them make a few appearances rather than not at all because whats the fun in not using something developed?
Though again, I realize much of what "Should" go into a campaign is what the PC's want, and is also up to personal preference. Some people like Monty Haul Dming. (giving out lots of loot and mostly only killing things. Lots of epicness with no real flare)
An interesting point in the argument for me was he asked the very same question. "Why does it have to be a god? Why can't it be the high priest of a god? What does it add to the story?"
Me and him are of differing oppinions, i think it being the actual god is more impressive. (in the example we were discussing getting a quest.) If it was straight from the god it definately adds to the story.
>.> After what the group has experienced with their first dragon or rather I have. (being captured in that room) I can truthfully say I doubt they would turn him down. XD I also don't plan on unleashing this fact for months to come down the road, and they'll have to figure out Skulh is a dragon by theirselves because he will continue to meet them obscurely or send others in his place. I just wanted oppinions from people, and I thank you for all who expressed them

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On a side note, no one shared their own bad guys? No one wants to share? xD