Spell damage (+X%) stacking

[Vellrad]

I got a question- how does damage increasing effects stack; I mean metamagic feats with items and enhancements.

Lets say i got:
-Maximize spell (+100%)
-Empower spell (+50%)
-Spell damage apmilification (for example fire and ice) IV (+40%)
-Superior something IX (+50%)

The items don't stack, as explained in description, so using Superior Inferno with Effiacy is pointless, but what with others? I bellieve they stack somehow, i get more damage when these all are turned on, but i can't guess how they stack.

If i add this all its normal damage+240%

My Polar Ray's average damage is about 450 (without) and 1,2-1,3k (with critical). My best Wall of fire (without critical) dealt 931 damage to Hambie. These are more than damage from spell description.

I tried to count them in another way: normal spell without any modification is 100%. Then i added 100% of its value for Maximize (i got 200% now). Then i added 50% of new value, etc. for total of 630% original damage, and this is way to much.

So if anyone knows, exactly how much damage do i deal, please tell me.

[shagath]

-Superior something IX (+50%)

The items don't stack, as explained in description, so using Superior Inferno with Effiacy is pointless, but what with others? I bellieve they stack somehow, i get more damage when these all are turned on, but i can't guess how they stack.

Superior Potency is +50%, Superior Combustion is +50% and Superior Inferno +75%(all superior clickies are really +75%, except efficacy). Neither of those stacks.

[Vellrad]

By "what with others" I was thinking about those i listed above.
Sorry for this missunderstanding.

[zyirius]

Maximized and empowered both apply to a spell but they do not "stack" they each add there bonus to the spells separately.

so a fire ball cast by a lvl 10 wizard

no meta magic 10d6
with Max spell 20d6 (+10d6 extra)
with emp spell 15d6 (+5d6 extra)
with max and emp 25d6 (+10d6 from max and +5d6 from emp)

[kernal42]

no meta magic 10d6
with Max spell 20d6 (+10d6 extra)
with emp spell 15d6 (+5d6 extra)
with max and emp 25d6 (+10d6 from max and +5d6 from emp)

Ish. 2 * 10d6 is not the same as 20d6; the former, for example, will have no odd damage numbers.

Stacking goes like this:
(Base) * (Feats) * (Enhancements) * (Items)
So CL 15 fireball, max'd, emp'd, +40% enhancement, + sup eff does:
15d6 * 2.5 * 1.4 * 1.75 = lots of damage.

Cheers,
Kernal

[zyirius]

Ish. 2 * 10d6 is not the same as 20d6; the former, for example, will have no odd damage numbers.

Stacking goes like this:
(Base) * (Feats) * (Enhancements) * (Items)
So CL 15 fireball, max'd, emp'd, +40% enhancement, + sup eff does:
15d6 * 2.5 * 1.4 * 1.75 = lots of damage.

Cheers,
Kernal

right double dmg good catch, but what item has sup eff at 75%? my item say 50% for sup eff.

oh and CL 15 fireball is still 10d6.

[kernal42]

Ah, indeed; I need to brush up on the low-level spells apparently.

The inferno/freeze/etc clickies (excluding efficacy) all give 50% more than they claim.
So Superior Inferno gives +75% spell damage, rather than the 50% in the description.

Or, if you're really well-geared, toss in the eardweller for +100%.

Cheers,
Kernal