Here's an FAQ for holy wars and religion. I look forward to reading any criticisms and discussions you guys might have on it over the next few days.
The file which lists what the holy war casus bell is in the following spot:
Crusader Kings II\Common\00_cb_types.txt
Search for "name = CB_NAME_RELIGIOUS"
My conversion of the code from paradox lua gamespeak to english is the following:
-You can't be pagan
-You can't declare a holy war on someone within the same realm
-In order for it to be valid, the target has to be one of the following, a heretic compared to your faith (catholic vs lollard and visa versa, not catholic vs orthadox though), or from a different religion group, or you're a muslim and they're a different type of muslim (the target of your attack must not be at war with non muslims)
-You can't declare holy war if your liege is not from the same religion group as you
-You can't declare holy war if your liege is the (exact) same religion as the one you're targeting
-Your liege either has to be the same religion as you, or you and your liege are both not heretics.
[improved from above list]
-You are the tribe of lithuanians(a pagan duke), you're attemping to declare a holy war, it's not going to work
Why: You are pagan
-You are an orthadox greek duke declaring a holy war on a miaphysite(different christian religion) duke in the byzantine empire(ruled by an orthadox emperor), it's not going to work
Why: Miaphysite isn't an orthadox heresy
-You are an orthadox greek duke declaring a holy war on a bogomolist(heresy of orthadox christianity) duke in the byzantine empire(ruled by an orthadox emperor), it's going to work
Why: Among other things, bogomolist is an orthadox heresy
-You are the fatamids (shia) trying to declare holy war on the seljuks (sunni) during their war with the byzantines, it isn't going to work.
Why: Muslims can't declare war on muslims while they are fighting infidels (aka people from another religious group)
-You are the fatamids (shia) trying to declare holy war on the seljuks after their war with the byzantines, it is going to work
Why: Among other things, muslims can usually declare war on any other muslims no matter what
Just a reminder, there's only 5 amount of relationships from one religion to another
Same: It's the same religion (catholic to catholic)
Heresy of: It's a "child" religion (catholic to cathar)
Parent of: It's a parent religion (cathar to catholic)
Same group: It's a similar religion from the same religious group (catholic to orthadox)
Different group: It's a religion that isn't concidered similar enough to be in the same religion group (catholic to shia, shia to pagan, anything etc)
Generally religions view each other the same way (bilaterally instead of unilaterally) except for parent and child religions. Cathars know they are a split from catholicism (but think they are newer and better), and catholics know that catharism is a split from them (but think they are older and better).
That said, the game files are not arranged according to age of religion necassarily, in doubt take a look at
Crusader kings II\Common\Religions\00_religions.txt
Even if you're scared of text files, that file is quite easy to read. Feel free to ask in this thread any religion's relationship to another religion and I'll check in the files the correct answer (and naturally if I'm wrong someone else will point it out fortunately).
Here's a list of religions by group in english in case navigating the following is too difficult:
crusader kings 2\common\religions
Formatting guide: Anything to the right is part of that subgroup, "x religion name heresy" is comments and is not a religion. E.g. cathar is a catholic heresy
Orthadox christian is also known as orthadox, shiite is also known as shia.
Christian Group:
catholic
-catholic heresies:
cathar
fraticelli
waldensian
lollard-
orthadox christian
-orthadox christian heresies:
bogomolist
nestorian
monothelite
iconoclast-
miaphysite
-miaphysite heresies:
monothelite-
/End Christian group
Muslim Group:
sunni
-sunni heresies:
zikri
yazidi
ibadi-
shiite
-shiite heresies:
bektashi
druze
hurufi-
/End Muslim group
Pagan Group:
pagan (not used)
norse pagan
tengri pagan
baltic pagan
finish pagan
aztec
/End Pagan group
Zoroastrian Group:
Zoroastrian
/End Zoroastrian group
The file which lists what the holy war casus bell is in the following spot:
Crusader Kings II\Common\00_cb_types.txt
Search for "name = CB_NAME_RELIGIOUS"
My conversion of the code from paradox lua gamespeak to english is the following:
-You can't be pagan
-You can't declare a holy war on someone within the same realm
-In order for it to be valid, the target has to be one of the following, a heretic compared to your faith (catholic vs lollard and visa versa, not catholic vs orthadox though), or from a different religion group, or you're a muslim and they're a different type of muslim (the target of your attack must not be at war with non muslims)
-You can't declare holy war if your liege is not from the same religion group as you
-You can't declare holy war if your liege is the (exact) same religion as the one you're targeting
-Your liege either has to be the same religion as you, or you and your liege are both not heretics.
[improved from above list]
-You are the tribe of lithuanians(a pagan duke), you're attemping to declare a holy war, it's not going to work
Why: You are pagan
-You are an orthadox greek duke declaring a holy war on a miaphysite(different christian religion) duke in the byzantine empire(ruled by an orthadox emperor), it's not going to work
Why: Miaphysite isn't an orthadox heresy
-You are an orthadox greek duke declaring a holy war on a bogomolist(heresy of orthadox christianity) duke in the byzantine empire(ruled by an orthadox emperor), it's going to work
Why: Among other things, bogomolist is an orthadox heresy
-You are the fatamids (shia) trying to declare holy war on the seljuks (sunni) during their war with the byzantines, it isn't going to work.
Why: Muslims can't declare war on muslims while they are fighting infidels (aka people from another religious group)
-You are the fatamids (shia) trying to declare holy war on the seljuks after their war with the byzantines, it is going to work
Why: Among other things, muslims can usually declare war on any other muslims no matter what
Just a reminder, there's only 5 amount of relationships from one religion to another
Same: It's the same religion (catholic to catholic)
Heresy of: It's a "child" religion (catholic to cathar)
Parent of: It's a parent religion (cathar to catholic)
Same group: It's a similar religion from the same religious group (catholic to orthadox)
Different group: It's a religion that isn't concidered similar enough to be in the same religion group (catholic to shia, shia to pagan, anything etc)
Generally religions view each other the same way (bilaterally instead of unilaterally) except for parent and child religions. Cathars know they are a split from catholicism (but think they are newer and better), and catholics know that catharism is a split from them (but think they are older and better).
That said, the game files are not arranged according to age of religion necassarily, in doubt take a look at
Crusader kings II\Common\Religions\00_religions.txt
Even if you're scared of text files, that file is quite easy to read. Feel free to ask in this thread any religion's relationship to another religion and I'll check in the files the correct answer (and naturally if I'm wrong someone else will point it out fortunately).
Here's a list of religions by group in english in case navigating the following is too difficult:
crusader kings 2\common\religions
Formatting guide: Anything to the right is part of that subgroup, "x religion name heresy" is comments and is not a religion. E.g. cathar is a catholic heresy
Orthadox christian is also known as orthadox, shiite is also known as shia.
Christian Group:
catholic
-catholic heresies:
cathar
fraticelli
waldensian
lollard-
orthadox christian
-orthadox christian heresies:
bogomolist
nestorian
monothelite
iconoclast-
miaphysite
-miaphysite heresies:
monothelite-
/End Christian group
Muslim Group:
sunni
-sunni heresies:
zikri
yazidi
ibadi-
shiite
-shiite heresies:
bektashi
druze
hurufi-
/End Muslim group
Pagan Group:
pagan (not used)
norse pagan
tengri pagan
baltic pagan
finish pagan
aztec
/End Pagan group
Zoroastrian Group:
Zoroastrian
/End Zoroastrian group