Guide: Guide to communions

[thejeff]

The manual, as far as I can tell, says nothing about how fatigue is divided in communions, other than that the slaves share the fatigue.

I tried doing some testing this weekend and what it proved to me was that I couldn't even get fatigue without communions right. The manual says fatigue should be the given fatigue for the spell times 1/(1+(magic skill - minimum skill)) plus spell casting encumbrance.

I tried this with Arcosephale, because I wanted to see how fatigue got spread around communions with various paths boosted and/or missing.

Before I even got to the communion I saw:
My prophet casting holy spells (0 fatigue) with 10 encumbrance, got a straight 10 fatigue every time.
A Priestess, with 3 encumbrance, got 3 fatigue for every holy spell.
Then she cast Protection, which is N1, 20 fatigue and gained 27 fatigue, not 23.

Mystics are also 3 fatigue and those with 1S also got 27 fatigue when casting Communion Slave
A Mystic with 2S got 15 fatigue from Communion Slave, not (1/(1+2-1))*20+3 = 13
Casting Body Ethereal, which is still 1S, but 30 fatigue, the 1S Mystic got 39 fatigue and the 2S got 21.

Once the Communion was up with 8 slaves, the Master cast PotS and got 6 fatigue. He started with 1S.
The slaves who started with 1S got 4 fatigue and those who started with 2S got 3.
I can't even try to calculate that out, until I understand the non-communioned results.

So, is the manual wrong about fatigue calculations, or am I misinterpreting something?

[Baalz]

I also tried to figure out how fatigue was calculated (before throwing my hands up and saying it wasn't obvious). On top of the things you mention I also saw weird stuff like different levels of fatigue on slaves who had the same magic paths and were the same unit type, and reinvigoration not removing all the fatigue from some of the slaves (or perhaps it removed the fatigue on some before fatiguing them for the casting, and some after). Some of this is probably rounding type differences.

All in all, my conclusion was that the fatigue calculations in the book were not exactly correct but were close enough for rough strategic planning. Use the formula you reference above (don't count encumbrance), divide by the number of slaves and that's *about* how much fatigue each slave will get.

[Torin]

The encumbrance added fatigue it´s twice the encumbrance according to the manual

[thejeff]

I don't have the manual in front of me, but I think it's only encumbrance from armor that's doubled. And that's reflected in the spell casting encumbrance shown under the detailed fatigue.

On first glance, it looks to me like fatigue from encumbrance is boosted based on the base cost for the spell. But not in any even or obvious fashion. I'll have to look at casters with different encumbrances.

[AlgaeNymph]

Baalz said:
Not sure I understand exactly what you're asking, but 8 slaves who have no fire magic will get a +3 boost, resulting in a fire level of 3.

But since the slaves never had any fire levels to begin with, wouldn't they incur a fatigue penalty without the phoenix power?

(I should've been clearer with my quote selection.)

[Baalz]

No, the slaves gain the communion bonus for all paths, including the ones they don't have at all - solely for the purpose of calculating fatigue absorbed through the communion. So that gives them 0+3 in this case, plenty to cast phoenix power.

[thejeff]

OK, I've figured out what I was missing in the basic fatigue calculations: Drain.

The real calculation is:
given fatigue for the spell time (1 + .1*Drain scale) times 1/(1+(magic skill - minimum skill)) plus spell casting encumbrance.
The battle I was examining took place in Drain 2, so for Body Ethereal, 30 * 1.2 = 36 +3encumbrance = 39
or 36/2 = 18+3 encumbrance = 21.

Communion fatigue makes some more sense now:
PotS becomes 120 fatigue/8 = 15
which is 15/4 = 3.75 ~= 4 for slaves with 1S(+3)
15/5 = 3 for slaves with 2S(+3)
Which is right
The master got 6, which isn't clear. 1S+3 +encumbrance should have been 7.
Encumbrance only applies to the master, but is also reduced somehow? Which makes sense, since I'm pretty sure some of the later spells only gave 1 or 2 fatigue.

[LDiCesare]

I wonder, if slaves' level is boosted for soaking fatigue only, what about the reverse communion?
You have a master and, say 8 slaves. The master leaves or stops casting. Do the slaves get the fatigue level boost for casting their own spells?

[Baalz]

No, the point of the reverse communion is that a bunch of level 1 mages get the benefit of power of the spheres and phoenix/earth/air power (and whatever other self buffs the masters cast). They gain no benefit implicitly from the communion as when they're casting spells they're doing so outside the communion.

So, a 1S 1F slave gets +1 F from the master casting phoenix power, and +1 from another one casting power of the spheres - this bonus (after it is in effect that is) is not tied to the communion. The slave acting on his own is now a level 3 fire mage and can cast falling fires. The master can leave the battlefield, or if he acts after the slaves can still cast spells without mucking things up.

[DrPraetorious]

One thing not mentioned in this article is the benefit of armored communions.

Communion masters generally carry valuable gems, possibly penetration boosting items, and seldom have to worry much about fatigue, obviously. So it's generally a good idea to protect your investment (vs. stray arrows, for example) by putting them in some armor.

This also goes to the question of how to protect a valuable communion if you are very communion dependent (for example, as Pythium or Ermor or Bogarus).

* Rune Smashers, Eyes of the Void and Spell Foci are all great for masters casting Shadow Blast or groovy stuff like master enslave.
* Masters spamming elemental attack spells want boosters, not for fatigue reduction, but for increased damage and/or area of effect. This is obviously true for most of them (note all the +s in the spell description) - what most people don't know is that the fatigue inflicted by the secondary wave (which is area 9!) from thunderstrike is also air-magic-dependant, so if you can push your air magic up higher it becomes much more devastating.
* A communion matrix is often a good investment even for a communion master who has astral. +1 turn of spell casting is a huge advantage, and for a big-spell communion, it is not expensive.
* 50% resistance to fire and cold more or less assure that you won't go down to a murdering winter or flames from the sky. Various combinations of armor and misc items grant this, but fire plate and a ring of ice is probably the cheapest way to go.

In the late game, murdering winter/flames from the sky are a virtual surety. If you have the Forge, absolutely forge fire plate and a ring of frost for each and every slave.