After months of wrangling with the developers and years of rumors we finally have definitive information about the upgrade formula's that go into using stones and runes to upgrade items. Read below for all the juicy details:

Smelting Stones (regardless of level)
Chance to Upgrade = 50% - an increasing amount for each + past 0
Chance to Break = 50% + an increasing amount for each + past 0

Heaven Stones
Chance to Upgrade = 60% - an increasing amount for each + past 0
Chance of no change = 20% + an increasing amount for each + past 0
Chance to break = fixed at 7%
Chance to degrade (-) = fixed at 13%

FAQ:
Q: Do ROP I, II effect the %'s in any way?
A: No. The rates listed above are unchanged regardless of using a ROP.

Q: Is it possible to break an item at +14?
A: Yes the chance to break is fairly high with a smelting stone and fixed at 7% with a HS.

Q: So it's easier to upgrade items the higher the + is?
A: No it is harder, the % to upgrade reduces each additional + added to an item.

Q: So what about upgrade events? What does 200% Upgrade mean?!?
A: An upgrade event alters the initial % value (50% for Smelting, 60% for HS) but it does not alter the subtracted value. What this means is that beyond the first few +'s there is no 100% even during a 200% upgrade event.

I am in the process of getting the same information for the new upgrade runes (purified and devil) and will post them when I get a chance. We will be changing the website and in game descriptions to reflect these revelations ASAP. Until then please spread the word to your fellow players, let the truth be told .

aeria_ks1lent wrote:

Smelting Stones (regardless of level) Chance to Upgrade = 50% - an increasing amount for each + past 0 Chance to Break = 50% + an increasing amount for each + past 0 Heaven Stones Chance to Upgrade = 60% - an increasing amount for each + past 0 Chance of no change = 20% + an increasing amount for each + past 0 Chance to break = fixed at 7% Chance to degrade (-) = fixed at 13%

Do we assume this is the case starting with EP2 or has this been in force since before? Any idea on what the change is with respect to the + value?

What effect has an upgrade event?

Heaven Stones
Chance to Upgrade = 60% - an increasing amount for each + past 0
Chance of no change = 20% + an increasing amount for each + past 0
Chance to break = fixed at 7%
Chance to degrade (-) = fixed at 13%


"60% - an increasing amount for each + past 0"
SO the higher you plus something the less likely a HS will be successful.

"60% - an increasing amount for each + past 0" SO the higher you plus something the less likely a HS will be successful.

No the opposite actually. I will edit the main post to be more clear.

The formula is

60% - Y= upgrade chance
where Y = a number that increases each + you have on your item already

So a +10 item has a lower chance than a +5 item, etc, etc.

aeria_ks1lent wrote:

"60% - an increasing amount for each + past 0" SO the higher you plus something the less likely a HS will be successful.   No the opposite actually. I will edit the main post to be more clear. The formula is 60% - Y= upgrade chance where Y = a number that increases each + you have on your item already So a +10 item has a lower chance than a +5 item, etc, etc.

... that's what I said- "the LESS likely the HS will be successful"

and what is this amount? It kind of sucks that we actually do not know what our chances of upgrading really are. The HS description tells us we have a certain % of success, since it's inaccurate it really should be edited as it is misleading.

so was anything changed with hs recently, or is this how its always been.

Thank you for getting the information, and especially for sharing.

One more thing to note. Based upon above formula it would seem that the most likely outcome of using an hs at +14 would be no change.

MescalitoCC wrote:

One more thing to note. Based upon above formula it would seem that the most likely outcome of using an hs at +14 would be no change.

That is correct (for a HS).