I (and any other programmers who join up as time goes on) will be using this thread to keep you informed on the progress of coding the system. I am creating this thread now because I have just rigged a basic concept of the thread system this evening:
http://nerr.g33k.org.uk/posts.php
It is exceedingly ugly, doesn't allow for posting yet, and certainly doesn't include any items or battling, but it does have the core, tree-based post code down, and the basics of the database hidden behind it. Click around and see how it functions, and let me know if this is the kind of thing people had in mind for the posting system.
Also, as time goes on I will be adding more pages to that subdomain as the general Nerr 3.0 testing ground. I'll keep you informed of updates as they happen.
Update 21/7/2012:
I've just finished the proof of concept for the battle system. It's a little different to some of the plans in the other thread since I started it before those were laid out, but I can tweak it if necessary.
http://nerr.g33k.org.uk/battle.php
I've populated the database with an initial set of items (including one marked as not a combat weapon, but that's for internal testing and later stuff and can't be used in this test) which you can use to experiment with the battle system. The system doesn't make a difference between attacker and defender - both users attack at the same time and the loser takes damage.
The type of weapon (Attack, Defence or Trap) determines whether or not the attack hits through a rock-paper-scissors system. The power is the base damage of the weapon. The element determines the final damage against the loser in the same way as the type, with a chance to double the base power, halve it, leave it unchanged or do no damage entirely. In a real fight each user wouldn't be able to see the other's weapon until the round completes, making it a game of luck and strategy to win the fight.
Have a play and see what you think. If people want extra items to toy with, let me know the stats and I can add them easily enough.