Use adventure-writing. However, I don't think we get may questions of the form "please help me fill in the blank in my plot." These are probably at great risk of being unsuitable for our site, and the questions' suitability will be case by case. I'm not aware of any guidelines we have on how to make these questions work.
We don't necessarily do well coming up with ideas for your games, because questions requesting ideas generally fall under a lot of our bad subjective criteria from our What types of questions should I avoid asking? help page:
You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page.
Your questions should be reasonably scoped. If you can imagine an entire book that answers your question, you’re asking too much.
If your motivation for asking the question is “I would like to participate in a discussion about
______”, then you should not be asking here. However, if your motivation is “I would like others to explain
______ to me”, then you are probably OK. (Discussions are of course welcome in our real time web chat.)
To prevent your question from being flagged and possibly removed, avoid asking subjective questions where …
- every answer is equally valid: “What’s your favorite
- your answer is provided along with the question, and you expect more answers: “I use
______, what do you use?”
- you are asking an open-ended, hypothetical question: “What if
- (a couple of these points skipped)
If you come to us with a question saying: "I have X circumstance. I need to do something. Does anyone have any ideas?", it's probably going to hit most of the negative points described above. A question like that is not a good fit for our site, and is probably better off asked on an RPG discussion forum or a chat room.
One basic requirement of our system is that questions should ideally have a single, objectively correct answer. Subjective questions (which comprise a large portion of our questions here) blur that requirement a bit, but you should still have requirements that allow us to objectively determine whether certain answers are more valid and correct than others. (If every answer is equally valid, voting becomes entirely subjective and our system breaks down in that question.)
So: make sure you have some specific criteria. Then, case by case, we'll work out what we can do.