Armor/Weapons

im having a few problems here with making weapons/armors.. i hope this is in correct section cause it might require triggers.. (trying to advoid triggers if all possible)


First

To Create a Weapon/Armor that
+ Atk
- Defense

but its not letting me - defense with items

or a Armor that
+Defense
- Speed

Yet again its not letting me put a -5 or whatever in the items abilities

please help..

Another thing

Making it so you can only have 1 type of a certain armor, weapon. (This is triggers needed.. any general ideas?)