There is also a DotF CB, inaddition to Holy War. The DotF is quite useful, for example, you can demand Return Core without Dip cost, which is exactly what I'm trying to do in my game - feed my Mamluks vassal with their cores in Ottoman territory.
For a while, the DotF CB was available in my game when declaring war, but now it it not available any more, even though all the tool-tips say that I have this CB against Ottomans (and other nations).
DotF CB expiring at some date is a possibility, yes, but I remember it was still available a few game-years ago - if has expired, then that would have happened just around 1640, and that is (afaik) not a year in which any religious features become unavailable. Also, if it has indeed expired, the DotF CB should not be listed in the tool-tips any more. Edit: I became DotF long after 1600, so that can't really be the expiry date.
# Defender of the Faith
cb_defender_of_the_faith = {
valid_for_subject = no
prerequisites = {
is_defender_of_faith = yes
is_neighbor_of = FROM
NOT = { religion = FROM }
cb_on_religious_enemies = yes
is_revolution_target = no
}
war_goal = defend_country_faith
}
defend_country_faith = {
type = defend_country
allowed_countries = {
religion = ROOT
}
badboy_factor = 1
prestige_factor = 2
peace_cost_factor = 0.75
po_release_vassals = yes
po_release_annexed = yes
po_return_cores = yes
po_revoke_cores = yes
po_gold = yes
po_concede_defeat = yes
allow_leader_change = yes
war_name = DOF_WAR_NAME
}
Are they are war with a tag of your faith? IIRC the DotF CB is only usable when you're intervening to defend a tag against the aggressor (normally you should be called in when hostilities break out, but if you got the title after the war had already broken out, this should be applicable).