Boo-urns...they lied about inferno

[Vash]

A recent Arreat Summit update said that inferno now has a flat 7 mana per second cost. After I rehinged my jaw, I immediately made an inferno sorc (and by immediately I mean earlier this evening).

Much to my dismay, I found that the mana cost increases to 8 at level six. However, I do have a staff that adds 3 to inferno. Perhaps +skills makes the mana cost go up. I haven't leveled enough to get inferno to a natural level 6 yet :D ...but I will test this out soon.

[CelticHound]

The cost should be in skills.txt. Let's see.

First, Inferno is an abnormal skill. It's got a 1 in the "repeat" column - the only others are Artic Blast (big surprise) and Blade Fury.

Inferno
repeat 1
startmana 6
minmana 0
manashift 2 (divisor = 64)
mana 36
lvlmana 1

Fireball (for comparison)
repeat (blank)
startmana (blank)
minmana 1
manashift 7 (divisor = 2)
mana 10
lvlmana 1

I believe the formula for mana cost is something like (mana + lvlmana * (slvl - 1)) * (2 ** manashift) / 256

To simplify the last half, let's substitute the divisor and get (mana + lvlmana * (slvl - 1)) / divisor

So for Fireball that's (10 + 1 * (slvl - 1)) / 2 or (9 + slvl) / 2 which gives the 5, 5.5, 6 ... progression.

Plugging in Inferno, we get (36 + 1 * (slvl - 1)) / 64 or (35 + slvl) / 64. My guess is that you pay 6 points to start the spell up and then the amount in the formula for each attack or segment of the inferno.

That's a start - now the knowledgable mpq readers can correct me.

-- CH

[Vash]

My guess is that you pay 6 points to start the spell up and then the amount in the formula for each attack or segment of the inferno.

Hmm...I've tried lightly clicking on my mouse button to try to create the shortest (time-wise) possible burst of flame. I noticed that my mana orb went down by only like 1 or so (instead of 6). Granted I have a couple of points in warmth, but I'm only level 8 or so.

[unless]

Figuring that the mana cost you calculate there is mana-per-frame, I took a look at the resulting mana-per-second costs for a couple skill levels.

1: 25 * (35 + 1) / 64 = 14.0625
5: 25 * (35 + 5) / 64 = 15.625
6: 25 * (35 + 6) / 64 = 16.015625

What caught my eye is that if you halve these values (and then round down in order to take into account lying-character-screen), they are consistant with the (admittedly few) data points Vash provides above. Slvls 1-5 show 7 mana per second, and slvl 6 displays 8. I have no idea at all why this might work this way; my only theory is that Inferno casts every second frame. More data is needed to confirm, and someone more well-versed in the game's inner workings is needed to explain.

Assuming that this is the way it works, inferno's mana cost will display as 8 for lvls 6-11, 9 for 12-16, 10 for 17-21, and 11 for 22-26, while actually costing very slightly more mana.


EDIT: Also, I'm fairly sure that the 'repeat' column means to continue casting without restarting the cast animation if the button is held down; that seems to be the common factor of the three listed skills. I don't think this impacts mana cost calculations.

[Vash]

1) The added mana cost was not because of the +skill on my staff.

2) The mana cost rises to 9 at level 12.

[Guest]

Ah, every half frame, that makes somewhat sense. Arctic Blast works the same way (it even does the fire damage sound!!), that would explain why I found it to kill monsters slower than a lower damage Hurricane.

Actually, from what I remember it has 2 streams, and you might only pay mana-cost for one of them? Eh, nevermind. *Waits for someone knowledgable*

[Vash]

Sigh...Arreat Summit updated and put in the correct mana cost for inferno. I don't know why I'm sighing...since it only goes up to 10 at level 20 =)