My next RTD is 75% (80%? 90%? hard to tell exactly) done with the rules writing and all the preliminary work figuring out exactly how the mechanics will work. Yay! Soon it shall overtake the RTD sub-forum, and obtain trillions of posts within days, breaking the interwebs.
My RTD, I just kind of jumped out of the gate with it. I did the mechanics as the need came up. >.> "Oh shit, I need health. Well, jacking DnD style health. Er, shit, I need levels or this will be the same thing forever. Ah, okay, I'll invent classes AND levels..." Needless to say, it got horrifyingly complex REALLY FAST.
Yeah, I did that with my first RTD.
I ended up adding/changing rules nearly every single turn, and although it wasn't a disaster, it was a huge pain in the butt not having worked out rules that would last through the whole game beforehand. It was my first RTD though, so I don't know if I could have (and it helped me work out what didn't quite work as well), but I really want the rules to be established beforehand and not to change during the game at all.
Eh, I feel like if I ever do an RTD, I'll make up the rules on the fly. I'm good at remembering inane things
I'd say good luck with that. I tried that with my IGYNPADCA rtd and and it fell apart before it even got started (although that was probably caused by that fact that I didn't really have any character creation rules and was trying to make them up based off of character classes and races made up by the players.) Unless you're really good at making up rules on the fly, I'd recommend having at least a some basic rules in place before you get started, and you should probably have them even if you are.
In related news, recently I've been planning on taking a second crack at the whole running an rtd again. I've been trying to come up with a system where every attribute is useful for every type of character, though I won't worry too much if I can't get that right. I also plan to implement rules to encourage dramatic play and some pvp (or, at least, players not being obligated to all group up together). So if I get around to actually doing it, it should be rather fun.
EDIT: Oh, fuck, I went into a new tab while my post was being posted and now it seems I've been ninja'd 20 times.