Well there are many variations for each gem color.
Typically,
Diamond (attack) : Gives x amount of attack stats (must have)
Amethyst (lifesteal) : Damages x amount and heals you that x amount on crit (also must have)
Ruby (crit) : Next 2 attacks always crit (randomly procs on attack) (nice to have)
There are some other types you can use but they are not good as the ones above
Amethyst (heal) : Just heals you x amount on crit (does not damage enemies)
Ruby (additional dmg) : Damages x amount (randomly procs on attack)
All other gem effects are kinda useless but some gems have stats (usually attack)
So people use those to increase their damage.
Majd persze kell sok masik is, de egyenlore a mostani contenthez ez eleg. Utoljára szerkesztette: Zarache87, 2015.12.28. 10:34:26