How do you calculate these % reductions?

• Phunkie wrote on 2011-01-16 06:28
  Say a Crystal Lightning Wand, upgraded for highest casting speed boost (-16%), with the Wand Jewelry Upgrade 1 Gem upgrade (-4%).
  
  That's -20% Mana Consumption for Lightning magic.
  
  
  Now with Lightning Mastery on its way next patch, R1 will grant an additional -20% Mana Consumption.
  
  1st charge of Thunder = 42 MP.
  
  With the upgraded (normal+gem) wand and R1 Mastery, the amount of MP used for the 1st charge of Thunder will be...
  
  42 - 42*20% - 42*20% = 25.2
  
  Is that correct?
  
  
  I read someone say that you don't add the %'s (-20% + -20% = -40%), you multiply them instead. But I dunno how that relates to this specific example.
  
  Anywho, clarifications?
• Zeo wrote on 2011-01-16 06:29
  I also heard that higher Ints you have, higher mana reduction % you get in G13..
  
  Can anyone confirm this.. and if so.. what is the formula for Ints and mana reduction?
• Kueh wrote on 2011-01-16 06:38

  Quote from Phunkie;292252:

  I read someone say that you don't add the %'s (-20% + -20% = -40%), you multiply them instead. But I dunno how that relates to this specific example.

  
  
  That wouldn't make any sense.
  
  If you multiplied them, then 20% from two different sources would cancel out and end up giving you 4% reduction.
• Phunkie wrote on 2011-01-16 06:44

  Quote from Whyrainfalls;292259:

  That wouldn't make any sense.
  
  If you multiplied them, then 20% from two different sources would cancel out and end up giving you 4% reduction.

  
  
  Well, I read this post and I was like what.
  
  http://mabination.com/threads/17053-how-much-INT-do-you-need-to-break-even-come-G13?p=278198&viewfull=1#post278198
  
  
  

  Quote from Justified;278198:

  I left out Magic Bolt Mastery then, since I forgot about it. Still don't know where "overruling" came from.
  
  In which case you get 17.62% Usage, or 82.37% Reduction.
  
  The point was that you don't add them together, you multiply. If you added 10% (Reduction Status), 49% (Tikka Upgrades), 20% (Ice Mastery), 20% (Bolt Mastery), 40% (Icebolt charges), then you'd end up with 139%. Meaning you'd have either 0MP Cost, or gain MP by casting magic.
  
  It's obvious that it doesn't work that way.

  
  
  When do you add, when do you multiply?
• Kueh wrote on 2011-01-16 06:49
  Well in that same thread, http://mabination.com/threads/17053-how-much-INT-do-you-need-to-break-even-come-G13?p=278965&viewfull=1#post278965
  
  

  Quote from Chiyuri;278965:

  If Cost type Do Stack togeter and that Both Bolt Magic mastery and elemental mastery are Cost Type reduction.
  it would give something like that(Ice Bolt final charge mana reduction is a Cost type)
  94.9% overall reduction when using ice bolt final charge. (Spell Innitial Cost - (Spell Innitial Cost X (10% + 20% + 20% + 40%))) X (100% - 49%) = Mana Used.
  It's still under 100%.

• Iyasenu wrote on 2011-01-16 07:26
  I think what he meant by multiply is (take 20% reduction for example)
  
  100 * .80 = 80
  Then take the second 20% (from mastery) 80 * .80 = 64
  
  That's multiplying.
  Adding would be:
  100 * (1.00 - (.20+.20))
  100 * .6 = 60
  
  
  I think it's multiplicative, not additive.
  
  
  And as for the int = mana reduction, I heard that was only for hailstorm.
• Chiyuri wrote on 2011-01-16 14:37
  I'll do testing once in G13 but I have to say this first
  
  Ice bolt final charge reduction and Mana Reduction Armor effect.. Neither Add or multiply... Ice bolt final charge reduction is 40% and the armor is 10%
  
  When only using the Armor.. you get 10% reduction.
  When using only the final charge reduction.. you get 40% reduction
  When using both.. you still somehow only get 40% reduction.
• Dixon wrote on 2011-01-16 15:30

  Quote from Chiyuri;292419:

  I'll do testing once in G13 but I have to say this first
  
  Ice bolt final charge reduction and Mana Reduction Armor effect.. Neither Add or multiply... Ice bolt final charge reduction is 40% and the armor is 10%
  
  When only using the Armor.. you get 10% reduction.
  When using only the final charge reduction.. you get 40% reduction
  When using both.. you still somehow only get 40% reduction.

  
  
  :l
  
  Icebolt only uses 4 MP. It's kind of silly to perform percentage tests on it, because the numbers are too small for anything significant enough to really notice, and lack precision.
• jking012 wrote on 2011-01-16 15:43
  Perhaps it works like this...heres an example instead of adding the -%'s together maybe its a coumpounded way of looking at it:
  justt go with the numbers for now
  
  100mp - [20%,20%,20%]
  =20+20+20= 60%
  100x.6 = 60
  100-60
  =40mp
  
  now heres my case
  
  100mp - (20%) - (20%) - (20%)
  
  100-20%(20)
  =80-20%(16)
  =64-20%(12.8)
  =51.2 mp
  
  60mp vs Compounded (51.2mp)
  
  perhaps mabi's mana reduc works like this compounded statment
  
  also at the multiplication theory.. perhaps its in calculation of the compound that it works? by decimal variations..
  100x .2 (aka 20%)
  =20
  =100-20
  =80x.2 (aka 20%)
  =16
  
  get the point?
  
  at least with this method you'll always pay mana for a spell and the % decreases will never truly be 100% no mana
  actually it reminds me allot of what the Physical defense %'s are like its not added but Multiple chances (not that im saying its like PD or anything lol)
• Kueh wrote on 2011-01-16 17:33

  Quote from Iyasenu;292299:

  100 * .80 = 80
  Then take the second 20% (from mastery) 80 * .80 = 64
  
  That's multiplying.
  Adding would be:
  100 * (1.00 - (.20+.20))
  100 * .6 = 60I think it's multiplicative, not additive.
  
  
  And as for the int = mana reduction, I heard that was only for hailstorm.

  
  
  Except that your very first line, if I'm reading things right, is addition.
  
  That .8, for 80%, if you got that by adding -20% to the full cost of the spell, then it's addition.
• gentrone wrote on 2011-01-16 18:00

  Quote from Dixon;292432:

  :l
  
  Icebolt only uses 4 MP. It's kind of silly to perform percentage tests on it, because the numbers are too small for anything significant enough to really notice, and lack precision.

  
  
  My point exactly.
  
  @Thread:
  
  Percentages compound. Mana cost reduction and mana consumption reduction are two different things.
  
  In example, a Reduction Set effectively reduces Mana Cost by 10%, so now the cost of the spell would be 90% of the original cost.
  
  Thunder would cost 0.9*42=37.8
  
  Since 37.8 is the new cost and a wand reduces consumption of that new mana cost, then an upgraded Crystal Lightning wand for -Mana consumtption would reduce that amount by 40% (which is 60% of the original cost).
  
  Which is the same to say 0.9*0.6*42=37.8*0.6=22.68
  
  Now, in the thread Phunkie quoted, we were discussing whether Magic Masteries provided -mana cost or -mana consumption.
  
  I think it would compound either ways, like this.
  
  0.9*0.6*0.8*42=22.68*0.8=18.14
  
  But Chiyuri thinks it would be like this (costs would add and then compound with consumption):
  
  (1 -0.2 -0.1)*0.6*42= 17.64
• Chiyuri wrote on 2011-01-16 19:12

  Quote from Dixon;292432:

  :l
  
  Icebolt only uses 4 MP. It's kind of silly to perform percentage tests on it, because the numbers are too small for anything significant enough to really notice, and lack precision.

  
  
  
  oh that.. when you think about it, it's not that difficult..
  Mana Heal quite slowly during day time without meditation. I just need to empty out all my mana then keep trying to cast as my mana heal up.
  I could count from 1 to 29-30 before I gained another mana. (not exactly seconds.. I counted with a tempo a little faster than seconds)
  
  Using Mana Reduction Armor, I could start casting ice bolt at 3 Mana and 18 count. (3.6 mana)
  Not using the Armor and casting only the last ice bolt which should be 40% reduction. I could start casting at 2 mana and 12 count. (2.4 mana)
  
  Now using both the Armor effect and casting the last bolt.
  If both reduction would add, it would be 50% right? 50% of 4 mana would be 2 mana.
  If both compount it would have been 46% reduction: 2.16 mana.
  What happened.. I could only cast after 2 mana and 12 count.. 2.4 mana in other words.