Welcome to the Phoenix Wright Justice For Some "roleplay" "community"! The only rule is, there are some rules! Also there are these rules:
1. You should make an account that represents a character, and then use them to create posts and comments! This is pretty important, and easily overlooked. A lot of people forget to do it and they go around telling their friends "I'm in the trendy new Justice For Some RP on Livejournal" and their more savvy friends ask which character they play, and they're like "Uh-oh! I forgot to play a character or make any posts!" Their friends then laugh. Do you like it when your friends laugh? Of course not.
2. Your character should probably be related to the Ace Attorney games in some piffling, peripheral way. Or lifted wholesale from them, we don't care. Completely AU versions of everything are encouraged, as you'll have noticed if you've had a look at the posts already in the community. You're welcome to play regular versions of the characters too, but bear in mind they'll still have to interact with, like, a version of von Karma who's made entirely out of jelly, and maybe an evil Larry Butz with guns in his hands, and things like that.
3. You can have as many characters as you darn well like. That's right, I said 'darn', and it was to emphasise how dang serious I am about that. It's probably more fun to have a bunch of characters so you can jump into any situation, rather than trying to find a realistic way to force one character into everything, because we are definitely all about realism here. Mention who plays them on their profiles if you want the fame, or omit it if you don't want the shame.
4. No spitting.
5. Don't post out of character unless you do it (along with some in-character stuff) in brackets or italics or French or whatever so people can differentiate. Unless you make a character whose whole gimmick is that they're constantly out-of-character, in which case don't post in-character. You knew the risks when you took the job.
6. You're not allowed to make a version of Winston Payne who's an anthropomorphic aeroplane and call him Winston Plane and every post is related to how he's a plane. This is a very specific rule. You can do things very much like this - for example, Miles HEDGEworth, where it's Edgeworth in topiary form, that would be really good - but you're just not allowed to do the one with Winston Payne as an aircraft. The reason for this is highly secret and if you found out you would probably die from the knowledge.
7. Doesn't it annoy you how even after you prove that the defendant couldn't have committed the crime, they're still declared guilty if you don't figure out the real "perp"? That annoys me a little. I mean, I'm a defending attorney! What do I look like, a prosecuting attorney?! GET A CLUE, MOM
8. Don't be a jerk. It's cool to play a jerk, but if that gets to the point where you're actually mailing dead animals to other people's real houses "in-character", you know you've crossed the line there.
9. You're welcome to godmode but also other people are welcome to say "Actually that didn't happen and my character is surrounded by an inpenetrable shield anyway and no tagbacks". I don't envisage this actually becoming a problem because few to none of us are seven years old.
10. Nine rules is pretty much a perfect amount. Going into the double digits is crossing over into the realm of pomposity a little.