To upgrade you first must find a Character Blacksmith or a NPC Blacksmith You also need to acquire some materials to upgrade your weapons and armor ----Weapons---- Level 1 weapons require Pharcon and add +2 to your attack for each upgrade Level 2 weapons require Emveratacon add +3 to your attack for each upgrade Level 3 and 4 weapons require Oridecon add to your attack for each upgrade +5 The Pharcon and Emveratacon can be purchased at the NPC Blacksmith but the Oridecon has to be found by killing monsters. ----Armor---- Only one metal is used for upgrading all armor...Elunium this also is found by killing monsters, and its the only way... Each time you upgrade Armor it adds 1 point of defense to that piece of equipment. ----Safety Limits---- Safety Limits is the max a weapon or armor can go without breaking...For Armor its +4, if you decide to upgrade even further, there is a chance that the armor will break. You CANNOT get the armor back when it breaks... For weapons it is different...Level 1 weapons have a safety limit of +7, Level 2 weapons have a safety limit of +6, Level 3 has a safety limit of +5, and level 4 weapons could break when you first try to upgrade it.

Updated: Upgrading level 4 weapons used to be safe before but since the many updates to the game, this is now the current chart for weapon upgrades: Level 1 weapons: safely upgraded to +7 Level 2 weapons: safely upgraded to +5 Level 3 weapons: safely upgraded to +4 Level 4 weapons: cannot be safely upgraded. Sorry about having to replace the old answer.