Drifter Bob said:
First, explain to me why I am stupid and this is NOT an example of anything being wrong anywhere except in my head (since I know nobody will agree with me) and second, tell me technically if I can give this thing a few bluff skill ranks (and no, using it as an unranked skill isn't going to cut it)
DB
1. Giving an Imp FREE skill ranks is a problem, becasue when I DO buy a game product I expect it to be rules correct. When I write something with the intent of sharing it with the D20 community I make sure its rules-right. Simply because that what SHOULD be done, what your're being paid for/trying to do. People PAY to have a book technically correct, not some writer's INTERPRETATION of the rules, since the DM who bought it's probably going to re-interpret the product for his own game (a analogy of a copy of a copy of a copy belongs here). That said...
I'd have no problem with the story you set out. It sounds really cool. But lets look closer.
First, I can pull off the "Help! Where's my MOMMIE" line so well my players won't even think to make sense motive rolls, so the Imp's lack of a Bluff ain't a problem. Now, if I had a Rules-Lawyer (I don't let them in my game)....
The various Alter Self/Alternate Form Spells give a +10 (?) bonus to disguise checks. Combined with the Imp's Cha, he might be able to make the check anyway. Sense Motive is an under-utilized skill that many characters ignore. You can give it Rogue Levels (or Bard), or up its hit dice/Int any number of things. Bluff vs Sense Motive ain't the achille's heel of your idea. The use the IMP encounter as the Keystone of the module is.
What if there is a Paladin in the party (or anyone with a Detect Evil spell). That'd cut the encounter shorter than any Sense Motive roll, harder to prevent too.
What you've designed is a one-trick pony. A really cool pony, but a pony. There's no way I'd run that in a party with a Paladin. I'd have to analize my particular party's Strengths and Weaknesses & see what the chance of my party seeing through the deception/attacking the imp/ or even caring about the girl are.
In the end, the d20 system, combined with the creativity of gamers, provides an infinite combonation of possibilites. In your example, an evil party might just kill the girl and loot the bodies (thus adventure ended), the cleric could try a Heal check on the girl (umm, that's not right, adventure ended). The Bard could Charm Person the girl to calm her nerves (imp immune, adventure ended), Paladin does Detect Evil to see if the foes are nearby (adventure ended). Cleric does Protection from Evil on the girl to keep her safe (adventure ended). Cleric gives her some water to drink, all he's got is Holy Water (adventure ended). Crazed Sorecer just decide to Magic Missle it, just to be safe (adventure ended). Heck the party wizard might be looking for an Improved Familiar and just give it a better deal. I could sit here all day and give way after way this adventure could fail without resorting to a Sense Motive check.
Your adventure is designed for a certain segment of the gaming population, the greatest service you can give your potential customers is to point out all the weak points that came up in play-test or spells/items that could kill the adventure before it began.
Off-hand I'd say about 50% of the parties I've DM'd for would be a good fit for your adventure. The rest might take the bait, or kill the imp.
However, I wish you luck on your endevor, post when it does come out, I'll take a look at it.
Vraille Darkfang