Additional attack

Could someone please explain exactly how additional attack works? What a higher percentage additional attack means and so on

 

25% chance (50% with secret chase) to trigger additional damage equal to your add. meele/magic% stat. Its damage is calculated just as skills damage, but isn't affected by crit or unsheathe, e.g. 300% additional meele is equal as a skill with 3 multiplicator. It uses physical proration and does no proration.

 

I'm sorry but you elaborate a little more on proration/ physical proration part? Not a clue on that lol. And where is secret chase at?

 

Additional attack has 25% chance to trigger after auto attack, but no proration. additional damage increase depend on what type of additional you have: melee and magic. melee depend on atk stat and physical proration, while magic depend on matk and magic proration.
there's a "secret chase attack" from battle skill lvl 4 to increase the chance to trigger additional attack (barehand skill also has a passive skill to increase additional attack, but only for bare hand, and i don't know how much it will increase)