Overview
How they work, and what they do. Not how to use them to win.
Introduction to Sabbaths/Communions 101
A communion or sabbath is the term for a group of mages casting the spells Communion Slave, Sabbath Slave, Communion Master, and/or Sabbath Master.
Sabbath Masters gain benefits from any mage who has cast Sabbath Slave or Communion Slave, and Communion Masters gain benefits from any mage who has cast Sabbath Slave or Communion Slave.
The Communion spells both require s1 (astral 1), and the Sabbath spells both require b1 (blood 1) and 1 slave, to be cast.
There is an E1S1 (earth 1 astral 1) item for 10 gems that makes someone a Communion Master at turn 0 of the battle, and one that does the same for making someone a communion slave – the Master Matrix and the Slave Matrix. These notably allow you to add non-S non-B mages to a communion, usually as masters, to cast a spell your regular communion mages don’t have the paths for.
Masters, whether communion or sabbath, pass on any non-encumbrance fatigue from spells cast onto their slaves, at 0.5x to 4x the amount of fatigue they would have taken (see: Fatigue Mechanics). This is spread equally amongst all Slaves and Masters, whether sabbath or communion. Masters also receive a boost to their paths depending on the number of slaves (see: Pathboost), which may allow them to cast spells they normally can’t.
The short version is that some mages become immobile paralyzed statues in order to add power to other mages. It’s a ‘communion’ as in a ‘joining’ of their magical powers to others.
The fatigue from Master spellcasting can cause a Slave’s fatigue go above 100. At 200, fatigue starts being converted into damage at a rate of <A LOT, 50+> of fatigue (or any part thereof, it rounds up) becoming 1 point of damage. This often kills the Slaves of communions or sabbaths where battles go on too long, or too many masters are added. It’s also why various strategies are used to renew the fatigue of Slaves – Soul Vortexes, Relief, Summon Earthpower, Reinvigorate, and why large and regenerating mages are considered excellent communion slaves (notably blessed and shrouded Skratti).
Any ‘self’ targeting spell a Master casts is also cast on every single Slave. This makes buffing your communion slaves very easy, and also contributes to the fatigue-reducing strategies outlined above.
Sabbaths
Sabbaths are only different to communions in that the initial spell costs a lot of fatigue, and they require a slave to cast. Thus they are slightly less common than communions, especially since blood nations tend to hoard their mages for blood hunting.
However, Blood has a powerful spell for communions and sabbaths known as Reinvigorate. This sets the caster’s fatigue to zero, and makes up for the initial cost of entering the sabbath if you script a master to cast it after all the slaves have joined (see: Turn Order).
That’s the only real difference – in every other respect, Sabbaths use communion mechanics and vice versa, and all sabbath slaves count as communion slaves and all sabbath masters count as communion masters and vice versa, the only difference is the spell used to enter one.
Communions
Communions work exactly like Sabbaths, but use s1 for their two spells, Communion Slave and Communion Master. That means any mage with astral-1 or better can join a communion as a master or a slave (or anyone at all with the master matrix or slave matrix item).
Some nations are referred to as ‘Communion Nations’, such as Arcoscephale and T’ien Ch’i because their most common mages all have at least astral-1 as well as many scattered or random paths, and thus rely on communions to boost their mages to the point that they can cast powerful or useful spells.
Due to the simplicity and ease of use of joining a communion, Communions see more use than Sabbaths, although for newer players, often their first communions self-destruct in amusing or horrifying ways – Phoenix Pyre propagating throughout a too-close communion and then a single mage being hit by an errant arrow and triggering a ‘chain-reaction’ of explosions is one such method, although the more common one is getting fatigue calculations wrong and losing all your slaves to fatigue-death.
Notable is the ‘suicide-communion’, where a few mages become Communion Slaves in a communion not designed to keep them alive – where it’s expected that they will die from accumulated fatigue at some point in the battle, but the extra-powerful and fatigue-less casts from the Masters that happen before that point will win the battle and thus justify their sacrifice.
In dom3 there was a tactic called a ‘reverse communion’ where a communion would be used to easily buff a lot of mages with ‘personal’ spells from communion masters and then the masters would retreat, leaving the communion slaves suddenly free to act with all their huge amount of buffs. Sadly, in dom4 communion slaves cannot act regardless of turn order and if all the Masters retreat they become fatigued/paralyzed/whatever and generally won’t recover in time to be of any use during the battle.
‘Communion’ is generally the term used to refer to any communion even if it’s formed solely of people casting sabbath master and sabbath slave. And as usual, sabbath masters can use communion slaves and communion masters sabbath slaves and so on.
Fatigue Mechanics, How (Not) To Kill Your Mages
Spells have a listed fatigue cost. Your mage takes that cost, plus his ‘spellcasting encumbrance’ (found by clicking on encumbrance in his unit entry) as fatigue when he casts the spell. If he has 1 path more than required by the spell (e4 for an e3 spell) he halves the spells’ fatigue (but not his spellcasting encumbrance) for how much fatigue he takes. Two more, one third. Three more, one quarter. And so on.
A communion slave takes the fatigue from a spell the master casts, divided between the number of communion slaves, and the master also takes that amount. So if a master, with fire-6 (some of it from the communion’s pathboost (see: Pathboost)) cast a fire-4 requiring spell with 60 fatigue, that fatigue would one-thirded to 20 for his extra paths, then divided by the number of communion slaves, let’s say four of them, so both the master(s) and all the communion slaves would take 5 fatigue. Not much, right?
However. There is an additional modifier applied to the fatigue going to the slaves if they have lower paths than the master. This is based on the relationship the slave’s path has to the master’s path (without any communion boosts, but with spell boosts, and item boosts), of the spell being cast. The modifier is a multiplier, and it goes x1 for equal paths between master and slave, x2 for master path higher than slave path but not twice as high(so a s1f1 slave and a s1f2 master casting a Fire spell would get a x2 fatigue of that slave’s share of the fatigue), x4 for master path twice as high as slave path (master path halved still higher than slave’s path, so f-4 vs f-1, or f-3 vs f-0, a slave with no fire path at all). If the slave has a higher path than the master, the fatigue is HALVED.
This can be summarized like so, and is all Sy’s information, so if it’s wrong, blame Sy.
slave level = master level: no modification
slave level > master level: fatigue / 2
slave level < master level / 2: fatigue * 4
slave level < master level: fatigue * 2
Base paths are what counts for this calculation, plus any path-boosting spells or items. The communion ‘pathboost’ is NOT counted.
So in our example, if the slaves were s1f1 and the master was s1f4, that’s a master level / 2 difference – that 4 fatigue would become 16 fatigue due to the x4 modifier. If the slaves were s1f2 and the master was s1f4, that’s a master level high than slave level difference, but not master/2 difference – 8 fatigue. If the slaves were s1f3 and the master was s1f4, that’s simple master higher than slave difference as well – 8 fatigue. If the slaves were s1f1 and the master was s1f1, that’s a no path difference – 4 fatigue. If the slaves were s1f2 and the master was s1f1, that’s a higher-than-master slave path – 2 fatigue.
Due to the ‘communion pathboost’, even a weak mage can become powerful as a communion master, which can lead to you using powerful mages as communion slaves, and weak ones as master, for an ‘endurance communion’. However, sometimes your ‘alphastrike’ of magical firepower is the main thing you care about so you will use weaker mages as slaves and too few of them to properly spread out the fatigue, and let them die so you can toss out a truly horrendous storm of magical death.
Every spell above 200 causes 1 pt of hp damage. Even a single point of fatigue above 200 per spellcast ROUNDS UP to 1 pt of hp damage. That means EACH CAST with slaves at 200 fatigue is a point of damage, no matter how little fatigue the cast cost.
I mean;
right?
Pathboost, And What It Means
Pathboost pretty simply means that the paths of your masters get ‘boosted’ by a number based on how many slaves you have.
And yes, Sabbath Slaves count for Communion Masters, and Communion Slaves count for Sabbath Masters.
2 slaves = +1 boost to ALL Paths of ALL Masters
4 slaves = +2 boost to ALL Paths of ALL Masters
8 slaves = +3 boost to ALL Paths of ALL Masters
16 slaves = +4 boost to ALL Paths of ALL Masters
32 slaves = +5 boost to ALL Paths of ALL Masters
64 slaves = +6 boost to ALL Paths of ALL Masters
And it tops out there, I think. You don’t get anything special for 128 slaves (you madman!).
This works mostly like having a higher path by any other means (empowering, randoms, getting booster items, casting a boosting spell) it makes spells scale higher with damage and such, gives access to spells that require higher paths to cast (although keep in mind the fatigue!).
How it differs is that you can’t spend gems with a ‘communion boosted’ mage to boost path by one as easily as one with that base path. A communion master can cast any spell that requires gems up to his communion boosted total – so a S3 mage with 8 slaves could cast a S6 spell that requires 6 gems (all mages are limited to their path in terms of gems they can spend, so a s6 (effectively) mage can only use 6 gems total per spellcast). But a mage with base Astral 6 could spend a gem to count as S7, and then up to 5 gems on the spell itself, where a communion-boosted mage cannot.
If a communion-boosted mage wishes to use an extra gem to boost his path in addition to gems on the spell itself, the TOTAL GEMS SPENT must be EQUAL TO OR LESS THAN his base path. So a S3 mage with 8 slaves, effectively S6, could only cast a S7 spell if it required 2 gems or less. One gem to boost, plus up to 2 on the spell itself, equals 3 – his base path in S.
This doesn’t stop him casting a S6 spell with 6 gems required. Or if he had 32 slaves, a S8 spell that requires 8 gems (such as Master Enslave). He just can’t spend a gem to boost his path by 1 if he’s already spending more gems than his base path.
So yes. ‘Why communion?’, you say? How about
Turn Order, And How To Abuse It
Mages cast spells in the order they are displayed in the ‘Army Setup’ screen. This is referred to as ‘turn order’, and is often used by players to do things like have someone up the top of the screen cast ‘Storm’ or ‘Light of the North Star’, then mages lower down on the same turn immediately utilize that widespread buff to cast things like ‘Summon Storm Power’ or ‘Stellar Cascades’.
With Communions, and given that many ‘Communion Nations’ are made of squishy humans, understanding turn order and how it applies to communions is very important. Things like on the first turn a bunch of mages casting communion slave and then a mage at the bottom of the turn order with a Master Matrix (so he has no need to cast communion master/sabbath master) casts Fog Warriors or Army of Gold to protect an army/magepile against Earthquake or Rain of Stones are very common. Also things like choosing a guy to be the head of a four-slave communion to cast LotNS and thus enable the Stellar Cascades-casting of the rest of the mages in the army as the guy at the top of the mage order, so on the turn he casts LotNS everyone else can Cascades.
Being aware of turn order can lead to various tactics, placements, or usages of buffs that are more effective than otherwise. It’s not as useful as for the various reverse communion shenanigans in dom3, but it’s still important. You can check turn order of units by order them to move to the same province and then pressing ‘y’ with that province selected – it show you a compilation Army Setup screen of all units in that province.
Suicide Communions
These communions use a few slaves that are expected to die with a lot of masters. Sometimes they have new slaves add themselves to the communion on turn 5, once the others are probably dead (or soon to die). This keeps the magic flowing much longer than with unaugmented mages, and gives them pathboosts – but it will kill your slaves. However, this can be worthwhile. When mages are worth less than winning the battle, this is your go-to communion.
Sustainable Communions
There’s three kinds of sustainable communions.
1. A communion you expect to last ‘long enough’ and not fill up your slaves with fatigue before the end of the battle.
2. A communion where the communion masters cast ‘communion slave’ as their fifth spell command, or are equipped with a bow and set to ‘fire’ rather than ‘cast spells’ as their 6th ongoing order, meaning they can only cast a limited number of spells.
3. A communion where the slaves have enough reinvigoration (via summon earthpower, items, or soul vortex or lots of hp + regeneration) that they won’t ever reach 200 fatigue no matter how long the battle goes on for.