Actually, as I see, the vassals don't change succession laws at all. In current law_events.txt, you finde law changes for feudal/regal supremacy laws, but not for sucessions. Then, you have the following events:
# 6614: Your vassals request a change to succession laws - a liege has to switch to election law
# 5520: Vassal demands establishing elective law - a vassal switches to election law
# 6640: AI event - Switching away from Gavelkind when ruler has too many titles
# 6641: AI event - Switching away from Primogeniture when primary heir is too weak
# 6642: AI event - Switching away from Elective when two or more sons
################################################## ########
# A vassal vassal accepts the sucession law of his liege #
################################################## ########
character_event = { # A vassal accepts female inheritance
id = 50100 # needs a decent number
picture = "event_law"
trigger = {
# You are a vassal, and a feudal one
condition = { type = ruler }
condition = { type = is_vassal }
condition = { type = form_of_goverment value = feudal }
# You do not allow females to inherit
condition = { type = not value = { type = has_law value = { monastic_supremacy = yes } } }
# Your liege does
condition = { type = liege condition = { type = has_law value = { monastic_supremacy = yes } } }
# Additionally, your liege is herself a female, has a daughter as his/her primary heir, or has royal preorgatory law
condition = { type = liege
condition = { type = or
condition = { type = gender value = female }
condition = { type = primary_heir
condition = { type = gender value = female }
}
condition = { type = has_law value = { royal_preorgatory_law = yes } }
}
}
# Some other conditions
condition = { type = not value = { type = trait value = proud } } # kind of a marker, to prevent recurrence
condition = { type = not value = { type = trait value = charismatic_negotiator } } # you are not witty enough to choose your own suc.law.
condition = { type = num_of_daughters value = 1 } # you have at least one daughter
condition = { type = loyalty value = 0.75 } # You are loyal towards your liege
condition = { type = not value = { type = has_law value = { elective_law = yes } } # You don't have elective law; otherwise your vassals would not like a law change
condition = { type = not value = { type = atwar } } # In peace. In war times, you don't have time for succession law changes
}
mean_time_to_happen = {
years = 300
# happens more often for counts
modifier = {
condition = { type = county }
factor = 0.75
}
# ... and not so often for duchies
modifier = {
condition = { type = duchy }
factor = 1.25
}
# You have lots of daughters
modifier = {
condition = { type = num_of daughters value = 2 }
factor = 0.9
}
# You have no vassals
modifier = {
condition = { type = not value = { type = has_vassal } }
factor = 0.9
}
# Youself have vassals
modifier = {
condition = { type = num_count_vassals value = 3 }
factor = 1.1
}
modifier = {
condition = { type = num_count_vassals value = 5 }
factor = 1.1
}
modifier = {
condition = { type = num_count_vassals value = 10 }
factor = 1.1
}
modifier = {
condition = { type = num_count_vassals value = 25 }
factor = 1.1
}
#balancing for difficulty level
modifier = {
condition = { type = not value = { type = difficulty value = 4 } }
factor = 0.8
}
modifier = {
condition = { type = not value = { type = difficulty value = 3 } }
factor = 0.9
}
modifier = {
condition = { type = not value = { type = difficulty value = 2 } }
factor = 1.1
}
modifier = {
condition = { type = not value = { type = difficulty value = 1 } }
factor = 1.2
}
# Prestige modifiers
modifier = {
condition = { type = not value = { type = prestige value = 0 } }
factor = 0.8
}
modifier = {
condition = { type = not value = { type = prestige value = -100 } }
factor = 0.5
}
modifier = {
condition = { type = prestige value = 500 }
factor = 1.05
}
modifier = {
condition = { type = prestige value = 1000 }
factor = 1.05
}
modifier = {
condition = { type = prestige value = 5000 }
factor = 1.05
}
modifier = {
condition = { type = prestige value = 10000 }
factor = 1.1
}
modifier = {
condition = { type = not value = { type = piety value = 0 } }
factor = 0.8
}
modifier = {
condition = { type = not value = { type = piety value = -100 } }
factor = 0.5
}
# Piety modifiers
modifier = {
condition = { type = piety value = 500 }
factor = 1.05
}
modifier = {
condition = { type = piety value = 1000 }
factor = 1.05
}
modifier = {
condition = { type = piety value = 5000 }
factor = 1.05
}
modifier = {
condition = { type = piety value = 10000 }
factor = 1.1
}
# Illness modifiers
modifier = {
condition = { type = trait value = illness }
factor = 0.8
}
modifier = {
condition = { type = trait value = stress_symptom }
factor = 0.8
}
modifier = {
condition = { type = trait value = maniac }
factor = 0.5
}
modifier = {
condition = { type = trait value = schizophrenia }
factor = 0.5
}
modifier = {
condition = { type = trait value = depression }
factor = 0.5
}
modifier = {
condition = { type = trait value = leper }
factor = 0.5
}
modifier = {
condition = { type = trait value = war_invalid }
factor = 0.75
}
modifier = {
condition = { type = trait value = intestinal_worm }
factor = 0.75
}
modifier = {
condition = { type = trait value = pneumonia }
factor = 0.5
}
modifier = {
condition = { type = trait value = plagueinfested }
factor = 0.25
}
modifier = {
condition = { type = trait value = clubfooted }
factor = 0.75
}
modifier = {
condition = { type = trait value = hunchback }
factor = 0.75
}
modifier = {
condition = { type = trait value = harelip }
factor = 0.75
}
modifier = {
condition = { type = trait value = lisp }
factor = 0.75
}
modifier = {
condition = { type = trait value = inbred }
factor = 0.25
}
modifier = {
condition = { type = trait value = coward }
factor = 0.75
}
modifier = {
condition = { type = trait value = modest }
factor = 0.75
}
# Other trait modifiers
modifier = {
condition = { type = trait value = generous }
factor = 0.75
}
modifier = {
condition = { type = trait value = valorous }
factor = 1.25
}
modifier = {
condition = { type = trait value = selfish }
factor = 1.25
}
# Talent modifiers
modifier = {
condition = { type = not value = { type = martial value = 2 } }
factor = 0.5
}
modifier = {
condition = { type = not value = { type = martial value = 5 } }
factor = 0.75
}
modifier = {
condition = { type = martial value = 11 }
factor = 1.15
}
modifier = {
condition = { type = martial value = 15 }
factor = 1.15
}
modifier = {
condition = { type = not value = { type = diplomacy value = 2 } }
factor = 0.5
}
modifier = {
condition = { type = not value = { type = diplomacy value = 5 } }
factor = 0.75
}
modifier = {
condition = { type = diplomacy value = 11 }
factor = 1.15
}
modifier = {
condition = { type = diplomacy value = 15 }
factor = 1.15
}
modifier = {
condition = { type = not value = { type = intrigue value = 2 } }
factor = 0.5
}
modifier = {
condition = { type = not value = { type = intrigue value = 5 } }
factor = 0.75
}
modifier = {
condition = { type = intrigue value = 11 }
factor = 1.15
}
modifier = {
condition = { type = intrigue value = 15 }
factor = 1.15
}
modifier = {
condition = { type = not value = { type = stewardship value = 2 } }
factor = 0.5
}
modifier = {
condition = { type = not value = { type = stewardship value = 5 } }
factor = 0.75
}
modifier = {
condition = { type = stewardship value = 11 }
factor = 1.15
}
modifier = {
condition = { type = stewardship value = 15 }
factor = 1.15
}
# Stability modifiers
modifier = {
condition = { type = stability value = 1 }
factor = 1.1
}
modifier = {
condition = { type = stability value = 2 }
factor = 1.1
}
modifier = {
condition = { type = stability value = 3 }
factor = 1.1
}
modifier = {
condition = { type = not value = { type = stability value = 0 } }
factor = 0.9
}
modifier = {
condition = { type = not value = { type = stability value = -1 } }
factor = 0.9
}
modifier = {
condition = { type = not value = { type = stability value = -2 } }
factor = 0.9
}
}
action_a = { # My liege is right. I will change the law.
ai_chance = 60
effect = { type = set_law value = monastic_supremacy }
# Sons dislike the law change
effect = { type = loyalty for = best_son value = -0.25 }
effect = { type = loyalty for = worst_son value = -0.25 }
effect = { type = loyalty for = random_son value = -0.25 }
# A law change makes you loyal
effect = { type = loyalty value = 1 }
}
action_b = { # No, I like my law as it is
ai_chance = 40
effect = { type = add_trait value = proud } # kind of a marker, to prevent recurrence
}
}
As you see, there are no events for vassals to"adopt" their liege's succession law. Just in some special cases, vassals change the sucession law, and they change it for some "reasons" (even if these conditions could be more precise).
Drachenfire's ambition is to "force" vassals to adopt the liege's succession law. Although I dislike this concept, it can be done via event:
Similar events must be written for the other succession laws, to fulfill Drachenfire's ambition.
Another ascpect, which needs testing, is to find out how the AI handles the succession law when you create a vassal. Will he "accept" the same law of group 0 as his liege's, or can't he read monastic supremacy as a succession law?
For this, please test as a king or duke, change to female inheritance and create some vassals. Then have a look into the savegame, if they have accept the female inheritence.
