So although this is SAO, this world has magic. This is obviously Alternate universe. So the fact remains that you are trapped in a world and death=perma death there is just magic. Now there are weapon qualities and from worst to best quality of metals is as follows:
Copper
Iron
Steal
Silver
Mithril
Each of the metals determine stats for a weapon. Though the stats may not all be better ex. Copper could do better damage than an Iron weapon but have less durability. Weapons will have qualities which are as follows
Name:
Mineral:
Damage:
Durability:
Level required:
Stats required:
Special effects:
Every level up you get 250 points to spend on your stats. (subject to change)