I hope this is the right place to put it...
Maybe a new sub-forum?
It should be called the RPG test drive section.
Basically, the idea is that before the RPG starts but after the Sign-Ups are done, the GM can make a "Test Drive" topic.
A test drive topic would basically be the beginning of the RPG, to see if the RPGers would contribute enough to it, so the RPG wouldn't die.
I think that it would stop the amount of dying RPG's in these forums.
Also, it could have something like a 4 page limit, so it doesn't go on for too long.
When the RPG would start, it'd start from the beggining, but there would be a slim chance of it dying.
Is it a good idea?
Well, I would have to disagree with this idea of yours. We already have a subforum for this, and it is called the RPG Cafe. People just don't utilize this method as they should, and only use the Cafe for informative purposes in their unique RPGs. For one thing, this thread: The
RPG IDEAS - Share your thoughts here, already does much of what you ponder. In there, you can post your idea, to see if it is likeable by the Serebiian masses of Serebii - Role-Playing Games Forum. If they do not like it, then you know from that idea, you will have zero to fifteen percent interest.
Another thing is, your 'test' idea can be implemented Via PMing systems another RPG Forum all together with your close friends (since links to outside forums are here by forbidden on this site), or Betaing with friends over a chat system, which I tend to do myself over my MSN messenger. To see if an RPG works, I get into character and role play over MSN in a group chat with a bunch of my friends who are also Serebii Goers.
Also, as friends are mentioned, you can always have a wingman, a back up plan, or someone you can rely on. This person in turn ussually becomes your Co-owner. With your friends as back ups, you can always be confident that they will help assist the RPG being alive; well if you know their character. I do admitt I have a few friends who are heavy procrasinators, and if the story doesn't revolve around them, they just don't care and you have to dangle them by a thin piece of thread off a cliff to get them to work... That's another story however.
A whole forum used for a singular task, that is small, could end up being extremely spammy, and chaotic, the Mods have enough on thier hands as is. It does have its benefitial aspects, but there are other topics and chances to use them outside of a paticular forum.
Also, this brings up a question about 'sign ups' for your 'test' rpg. How will they be constructed? I personally prefer betaing with friends over MSN to see if my RPG is doable, I even get people I rarely talk to to see what they think.
But besides that, this idea will not, I assure you, lessen RPGs from dying. It might, in fact, give a deeper would to the RPG forum, by having less 'official' RPGs actually starting, for in my course of being on Serebii, I've only seen two RPGS finish, I can't remember the other one, but I know that Scar's Sonic RPG was one that completely finished.
RPGs will die out due to a variety of reasons, not just lack of interest; which you have to be careful to who you reserve adn sign up. When I construct a serious complex RPG which I am serious about, I make my sign ups more complicated for I want those who are very ambitious to join them, telling me a sign that they won't loose interest. An example of that is Cdra1617, and Mine's Kingdom Hearts RPG, Tundra, if I may use his name, posted a very good sign up, well it was small at first, but her kept adding and adding and adding to it, showing how ambitious he was in wanting to join our RPG. I would have members of his passion rather then the Bestest RPGer who signs up for RPGs, has incredibly skill, but can rarely post due to "lack of modivation."
I know we all loose our sparks, and it could be a major reason to why RPGs die, but you must also take in consideration of time. This Site is origined in the United Kingdom, but is International, every time zone applies to this forum. People from around the globe can access this forum in differant times, and a sad fact is, that the usual lag of this forum can occur during their best chance in entering these forums, the lag prevents them from viewing the forum, or makes Serebii so slow that they get fed up with it.
I personally don't have the problem cause at early night, it works fine for me, but others it can be hectic with.
Also, we all have lives, and scedules. People have their examininations and well other things at differant times. One thing a Game Administrator might take into consideration is when is the perfect time to post their RPG? I know a lot of people who post it the same day they make it, they tell me "Oh, I took five hours on it, its good." I would spend, well yes, five hours on it minimum, but over teh course of a week, and would post the RPG when the timing is right to get max amount of member participation.
You will notice that more rpgs are created and survive longer during summer months, you know why? People are more free with time.
Time is a major reason for why RPGs die.
so you can't cure lack of interest, or time, or any other matter with this new sub forum. Those are obstacles you must fend for yourself with. If the RPG is meant to go one, it will go on, if YOU want to keep your RPG alive, and no one has posted in awhile, under certain circumstances, like a plot moving post, you are allowed to double post. Also Pming the members who are inactive in your RPG does not hurt as well.
There are many treatments and stallers for the unavoidable death or ending of an RPG, but you yourself but implement the shots, I know mods are gods, but faith, alone, can only get you so far.
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WELL, after realizing my small rant, I've also been thinking of something to do with the rules, a slight modification, but have been a closet viewer about it. A few of us members have talked amongst ourselves, and I guess I'll just post the idea, lol:
5. Sign Up Length
Sign Up Forms should have at least 4-5 sentences in any fields regarding Description, Personality or History (if included). Usually if it is under this minimum it means you should have worked on it for a bit longer.
I just have a few oppinions and concerns about this rule, a possible suggestion if you agree. I am not demanding nor saying that it should be changed. I am just giving a moderate oppinion.
The fifth rule, I do think needs to be edited from sentences, to lines. I have seen all to many mods closing sign ups due to sign up sheets being incorrect and plots too small. Yet, five sentences minimum and be as small as this:
Jim is a tall boy. He has brown hair. Jim also has brown eyes, that sparkle. Jim always has on a red shirt and blue pants. He has his favorite sneakers on too.
Looking at it, this is legal, it has five real sentences. How short is it? To me its barely even on the second line, yet the RULES clearly state that sign ups need to be FIVE sentences minimum, not five LINES or etc. So
My suggestion is change the 'sentences' word into 'lines.' If not five lines, possibly four lines would work. 
