Case by case, eye of the beholder stuff. I don't think you can give any followable guidelines that wouldn't be seen as draconian.
Dec out.
If you're familiar with US broadcast television, then aiming for prime time TV sitcom levels is probably your best bet. Don't forget that you can leave a lot the player's imagination without explicitly describing or showing it. A little innuendo can go a long way.
<QR>
As a general rule, since the game is rated T for Teen, if it wouldn't fly for a PG-13 movie or TV show, it's too risque for MA.
New story arcs coming soon (ARC IDs will be aded when I finish the arc):
So, you want to join the Hellions? (level 1-14 Villainous arc)
Sparks & Steel (level 5-20 Heroic arc)
and
So you want to join the Skulls? (level 1-14 Villainous arc)
Do our profanity filters work in MA?
If so, you shouldn't have a problem with language since individual users set that for themselves.
If not, I wouldn't even curse because children play.
Considering we can't even swear.....Probably G rated?
[ QUOTE ]
Do our profanity filters work in MA?
[/ QUOTE ]
No, they do not that is to say, the profanity filter does not check mission text, NPC dialogue, or clues for profanity.
When you are in the Architect you'll see an error pop up indicating there is a problematic word. For instance, if you type the word "buttress" the first four letters are "butt."
Mind you, "butt" is not considered a profane word; it's just an example. I'm sure you can imagine similar words ("assistant") that might set off the filter. Try it yourself and see.
Good to know. And while I could tell you in private a very easy workaround for this, forum rules mandate that I would then have to terminate you. So Mum's the word. 
Of course there are a dozen ways to get around the profanity filter, by using stuff like 'P3N1S' and 'B00BS'. Every 3rd grader knows this by now :-)
But, I'm not interested in potty humor, I want to know how deep into naughtyville your story in can go. Prime-time sitcom is OK, but how about Family Guy naughty? Late-night cable? Showtime? HBO?
No one can answer that question. Likely even a redname can't. You just have to use common sense, remember the game's rating, and see what happens.
@Doctor Gemini
Arc #271637 - Welcome to M.A.G.I. - An alternative first story arc for magic origin heroes. At Hero Registration you heard the jokes about Azuria always losing things. When she loses the entire M.A.G.I. vault, you are chosen to find it.
Chances are that if you have to ask, then it is too risque.
That would be my assessment, as well.
Also, think about this: How much of the innuendo is actually NEEDED for the story? If a lot is needed, either for humor or plot development, then the story as a whole might need to be toned down a bit.
Now, granted, I've no issues with 'adult themes'. But if you have to ask yourself, "Would someone's mom freak out if she caught her kid playing this, as opposed to the regular content?" then it's probably a bit much.
"City of Heroes. April 27, 2004 - August 31, 2012. Obliterated not with a weapon of mass destruction, not by an all-powerful supervillain... but by a cold-hearted and cowardly corporate suck-up."
Well, I've published my oh-so-risque story: "Two Chicks at Once", mission #83920. Please take a look and tell me if you feel it's over the top; I'd rather hear it from forumites then a GM.
After having read the article on Gamasutra (Clicky) I'm glad that the devs are implementing a less than Draconian policy on user content, but OTOH, I'm concerned that we haven't been given any guidelines on exactly what is and is not allowed.
I'm planning a mission arc that is somewhat risque, but still nothing you wouldn't see on TV. (Not even HBO levels... Fox maybe.) I wouldn't mind trimming it in places, but I really, _really_ don't want to have to pull the whole thing for being out of bounds. Can someome give me some idea of what we can't do? Dev input would be greatly appreciated.