Just an Idea I Find Exciting...
So, I was thinking about the Materia System, and this idea struck me: Why not reuse FFIX's leveling system?
A huge amount of armor and weapons would be needed. These would get put into classes. Like, Bronze, Brass, Iron, Steel, Silver Longswords.
Equipping any piece of armor or any weapon allows for the ability (passive or active) to become available.
These abilities are lost once the item is unequipped. To save abilities, one must earn Equipment Points. For example, when equipping a Hoplon-class shield, "Shield Bash" becomes available. The Equipment Point bar for "Shield Bash" needs to be 100% full to use the ability without that item equipped.
Now, the Blue Mage system from FFXIV comes into play. Physical levels earned reward points for abilities (passive and active) and certain levels must be obtained to equip certain items. So, at level three, one can equip a Bronze Hoplon and learn "Shield Bash I." At Level 13, the Brass Hoplon has "Shield Bash II" available. These abilities would scale, so "Shield Bash II" generates more agro or something.
Furthermore, passive stats and abilities can be earned from the same system. That same Bronze Hoplon has "+3 VIT" on it. Let's say, at level 3, one has nine active ability points and nine passive ability points. So, you equip "+3 VIT" for three passive points and "Shield Bash I" for three active points. The rest of your equipment, from your earrings to your helmet, offers abilities, as well.
Perhaps an ability decay system would be needed too. If one learns Taunt from their Bronze Helm, but hasn't used Taunt after accumulating a certain amount of physical experience, then the ability degrades in mastery. Remember, once it falls beneath 100% mastery, one would need to equip another Helm-class head-equip to earn back those Equipment Points. I think this would balance out something like a full-plate wearing, greatsword wielding warrior-mage, for he'd not be able to use every ability in combat. Even if someone wanted to deal damage, tank, nuke and heal, that person would eventually be stretched too thin, and wind up being sub par in
all areas!
The Materia System will compliment this nicely.*
* If you can convert that same Bronze Hoplon to a "Materia Thing That Gives +2% to Defense" and then equip that "Materia Thing" to your Brass Hoplon, it would compliment it nicely. I have no idea what the Materia System will actually be like, so this is just as much speculation as my prior comments are nothing but hopes and dreams.
TL;DR: Read more; it's good for you and for us!