Son of a %^&#$^
I looked all over for more mana reduction/pts. even did a search and somehow did not see that.
I’ll file it because it’s definitely saying 2. I thought that was the proper math but then it’s not my forte so figured I didn’t understand the formula.
I agree 1000% with you the highlight/search should be brighter. I want big flashing arrows and an orchestra.
It’s not mana cost reduction the node gives it’s mana cost efficiency. It’s not the same calculation
Should be: New Mana Cost = Old Mana Cost x 100/(100+Mana Efficiency)
Works like CDR
That still works out to be 1.25 in my estimation.
Old 2 mana
60% mana efficiency
2 x (100/(160) = 1.25
So if this is correct math, than it looks like it is rounding up, not down. Is it supposed to round up?
Yes, it always rounds up.
Ah, I didn’t check the node. But yes, I know how that works.
FYI: Unity uses banker’s rounding by default (it rounds to the nearest even number) – this is used almost everywhere in LE UI where numbers are rounded.
Okay this is why math breaks my brain.
Are you saying in order to get an odd number like 1 or 3 you have to land on it exactly? Otherwise you’ll only get evens?
Like 1.01 or 2.99 will both round to 2?
Is this why some of those early +n skills on weapons were making it almost impossible to get the highest range on them?
I’m thinking that he meant the nearest “whole” number instead of the nearest “even” number. Correct @Dammitt?
Not exactly. Banker’s rounding is sometimes referred to as “rounding to even” or “rounding to nearest even”, but in fact it’s just rounding ties to the nearest even number which basically means numbers ending with 0.5.
Mainly this could cause confusion in cases when some value is calculated and then displayed rounded. Usually when you have some rounding you would assume that 1.5 would round to 2 and 2.5 would round to 3, but in case of banker’s rounding they both would round to 2.
So if for example there’s a skill that costs 3 mana and there’s a node / item mod or whatever that increases its cost by 50%, then it’s mana cost would be 4.5. In UI mana cost is displayed as integer, so even if one might think that it will be displayed as 5, in reality you would see 4.
Okay, that makes…‘sense’. 
Next question. So in the very particular case I was seeing with Frost Claw where it was showing me 2. By the actual math calculation it’s 1.25.
This is apparently being rounded - for display - to 2. Does this mean it’s costing 2 mana or on the backend does it know it only costs 1.25 and that is the ACTUAL number being calculated?
No, the rounding is only for display purposes. The game uses the calculated mana cost (or etc) when the skill is used.
Uh, just checked and seems like I chose a wrong stat for giving an example. Mana cost / channel cost in tooltips are rounded via Mathf.Ceil(). Stats in character sheet on the other hand are rounded via Mathf.RoundToInt(), which uses banker’s rounding.
As for the used mana cost, Llama8 is correct, internally it’s just floats, so it uses 1.25.
You want to spec into FC and EN. You need those 8/8 Ignite chance points in EN. Plus you can take the absolutely crazy good node in EN called ‘Infernal Nova’ to make it screen-filling, and also boost its Ignites through the roof, and you do NOT suffer the cooldown that this node will normally add.
For my build I went with…
Frost Claw
Frost Wall
Glyph of Domination
Elemental Nova (specced but not on skill bar, procced by Frost Claw)
Flame Ward (specced, but not on skill bar, procced by Frost Wall)
Flame Rush (on skill bar but not specced)
Runic Invocation (on skill bar, but not specced, only used to force cooldown of Glyph and facilitate Edict of the Scion passive node)
Yes you need mana management with FC. As you will recall, your best in slot weapon for this build is Firestarter’s Torch, which comes with -4 mana cost to all Fire skills already. Aim for Spell Damage and Reduced Mana Cost prefix on it via LP. I have that setup and my Frost Claw costs 0 mana.
You can also put points into Warmth in Flame Shield to help further with mana.
A final thought on favouring Frost Claw… it is well worth pursuing it if you can manage the mana, as it also has a nice +18 ward every time you cast it (from the Shiver Shell skill node). That adds up to a lot of ward.
My current build (happy to accept criticism):