Here is a 12sky2 tips guide about Upgrading for new players.Hope it is useful to you.

1. The catalyst used must either be one grade less/equal or many grades higher than the equipment you're upgrading

2. If you fail an upgrade, only the catalyst and force core (or upgrade cores) used will be gone. The equip you're upgrading still remains.

3. The best lvl 1 Upgrades are hp and critic dmg! (you can only add hp on suits and boots and critic on helms and weopens)

4. Gloves are realy special because u can add nothing realy good, many choose Attack+2 or def+2 but u should try a lvl 2 upgrade on gloves (maybe 2% Hp steal or max critic rate 2%)

5. "Sword/Magic Amp", "Skill exp +4" or "2 Slot item drop times" in a slot are drops from mobs only (means all mobs have a certain chance for such a drop)

6. First chance to get a succes is 75% (if you have a double slotted item the second slot will have a 50% chance)

7. You Only should use low cores if u want to increase the succes rate!!! (You Will save some money)