Author Topic: How spell damage is calculated  (Read 9387 times)

Offline Gamgan

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How spell damage is calculated
« on: October 05, 2009, 02:13:14 PM »
TL;DR
(base + type 3 + sp dmg * sp dmg mod) * crit mod + focus * base

base = spell's base damage
type 3 = type 3 augment bonus
sp dmg = spell damage mod3 (for spells within 5 levels of the character)
sp dmg mod = (cast time + recast time) / 7, for beastlords we get a 4.378x multiplier for spell dmg
crit mod = crit dmg multiplier due to destructive fury
focus = spell damage focus

Parses left to do:  Bard aura/spell damage buffs, Glyph of Destruction effects, spell damage's affects on weapon procs

Validation (parses):

Crit mod:  All gear unequipped

               spell               norm      crit      crit multiplier
Jagged Torrent Rk. III159435863586/1594 = 2.25
Frigid Lance Rk. III199244824482/1992 = 2.25
Bite of the Vilrik Rk. III437698469846/4375 = 2.25

crit mod bonus for Destructive Fury rk 3 = 25%

Spell Damage:  No damage focus or type 3 items equipped.  Total of 172 spell damage from items.

               spell               norm            norm bonus            crit            crit bonus      
Jagged Torrent Rk. III1594035860
Frigid Lance Rk. III27452745-1992 = 75361766176-4482 = 1694
Bite of the Vilrik Rk. III51295129-4376 = 7531154011540-9846= 1694

Both of our lvl 80+ nukes receive 753 extra damage for non-crit hits and 1694 for crit hits for 172 spell damage equipped.

1694/753 = 2.25

Confirmation that spell damage bonus is affected by critical damage multiplier.

753/172 = 4.378

Each spell damage adds 4.378 damage to the spell for non crit hits, and 4.378*2.25 = 9.85 for crit hits.  The forumula for calculading spell damage seems to be [cast time (in seconds) + recast time (in seconds)] / 7, in this case it would be )30+0.5)/7 = 4.357, close enough for our purposes.

Type 3:  No damage focus items equipped.  Total of 185 spell damage from items.

               spell               norm      expected norm (wo/ type3)      norm bonus
Jagged Torrent Rk. III17051594 (same as base)1705-1594 = 111
Frigid Lance Rk. III29401992+4.378*185 = 28022940-2802 = 138
Bite of the Vilrik Rk. III54904376+4.378*185 = 51865490-5186 = 304

Type 3 adds as much as they say to normal hits.

               spell                  crit      expected crit (wo/ type3)      crit bonus
Jagged Torrent Rk. III38363586 (same as base crit)3836-3586   = 250 (250/111 = 2.25)
Frigid Lance Rk. III66152802 * 2.25 = 63046615-6304   = 311 (311/128 = 2.25)
Bite of the Vilrik Rk. III123525186 * 2.25 = 1166812352-11668 = 684 (684/304 = 2.25)

Type 3 adds 2.25x stated amount to critical hits.  Confirmed that crit multiplier affects type 3 damage bonus.

Frigid Lance type 3 is essentially the same as having 31.5 spell damage, while Bite of the Vilrik type 3 is the same as having 69.4 spell damage.

Focii:  All gear equipped, 90% cold / poison focus, 212 spell damage.  Due to the random nature of the focus values, a larger sample of casts were parsed than for previous figures.

Bite of the Vitrik Rk. III, base damage: 4376
Expected normal damage (with type 3 and spell damage): 4376 + 212*4.378 + 304 = 5608
Expected crit damage: 5608 * 2.25 = 12618

#      exp         min         min bonus      avg         avg bonus         max         max bonus         damage increments
non-crit:575608570397 (2.2%)76312023 (46.2%)94663858 (88.2%)43-44 multiples
crit:181261812942324 (7.4%)145781960 (44.8%)165303912 (89.3%)43-44 multiples

Crit rate = 24%

Jagged Torrent Rk. III, base damage: 1594
Expected normal damage (with type 3): 1594 + 111 = 1705
Expected crit damage: 1705 * 2.25 = 3836

#      exp         min         min bonus      avg         avg bonus         max         max bonus         damage increments
non-crit:591705172015 (1.0%)2370665 (41.7%)30751481 (92.9%)15-16 multiples
crit:163836385115 (1.0%)4572736 (46.2%)52541418 (89.0%)15-16 multiples

Crit rate = 21.3%

Frigid Lance Rk. III, base damage: 1992
Expected normal damage (with type 3): 1992 + 212*4.378 + 138 = 3058
Expected crit damage: 3058 * 2.25 = 6880

#      exp         min         min bonus      avg         avg bonus         max         max bonus         damage increments
non-crit:583058308527 (1.4%)3975917 (46.0%)48181760 (88.3%)19-20 multiples
crit:176880691737 (1.9%)78861006 (50.5%)86701790 (89.9%)19-20 multiples

Crit rate: 22.7

Eventhough the non-crit max bonus appears to be 92.9%, which is more than the 90% focus, the damage increment multiples suggest that neither the type 3 or the spell damage modifiers are considered when calculating the 90% spell damage bonus from focii.

Average crit rate: 22.7%

Expected dps increase from spell damage mod3 (main purpose of this parse)

crit rate * crit dmg multiplier * dmg boost from sp dmg + non-crit rate * dmg boost from sp dmg
0.227 * 2.25 * 4.378 + .773 * 4.378 = 5.62

So, for each lvl 80+ nuke cast, we can expect a 5.62 damage boost for every spell damage mod3, assuming no spell resists, bard songs or glyphs.  Since we have 2 80+ nukes, on average we gain 11.24 extra spell damage per spell mod3 every 30 seconds, which translates to 0.375 DPS increase.  To put this into perspective, I currently have 212 spell damage, which would translate into 79.4 DPS boost.  Not all that impressive, but it's probably still one of the more useful stats on raid gear.  Spell damage also has an affect on proc damage, but I haven't parsed it's effectiveness yet.

Side note

I have done some parses with a wizard buddy, who seem to receive smaller benefit from spell damage mod3 stats than we do, and it even varies from spell to spell in their lineup.  Info from those parses which may be relevant for beastlords is the effects of Destructive Fury.

                  spell                  norm         crit         calculation
Flashblaze III70012065220652/7001  = 2.95
Ethereal Combustion III128263783637836/12826 = 2.95
Ethereal Iceblight III117703472134721/11770 = 2.95

crit mod bonus for Destructive Fury rk 15 = 95%

Roughly 5% crit damage bonus for each rank of Destructive Fury after rank 3.

P.S.:  Whoever the idiot was who came up with how to define tables for forums with this code needs to have something really bad happen to them.
« Last Edit: November 18, 2009, 05:17:55 PM by Gamgan »

Offline Khauruk

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Re: How spell damage is calculated
« Reply #1 on: November 29, 2009, 07:48:09 PM »
Stickied now, and thanks much for posting this.
TURNCOAT!!!!!