Hello!

The v4.6 update includes some AI faith conversion changes, which I will tweak in future as and when required - including perhaps adjusting them relative to particular game rules.

Generally you should now see less drastic conversion between faiths within the same religion groups, and especially when they are not fundamentally opposed to one another. The aim here is to have less immediate religious flip-flopping, and somewhat more historical outcomes.

For example, Sunni and Shi'a rulers will no longer try to convert provinces that are of sub-faiths within their own branch of Islam; so if a ruler is Ash'ari and they have Maturidi provinces within their domain they'll be less likely to try to convert them all, as they still view them as Sunni. The same is true for Shi'a rulers with sub-faith provinces, such as Isma'ili and Hafizi. There are exceptions to this, such as if the ruler's faith is Fundamentalist, or has either the Ecclesiarchy or Unrelenting Faith tenets, or the province being converted is a holy site.

Muhakkima and Zandaqa rulers are not affected by this, and will still try to convert one another's provinces to their specific branch regardless.

Another change here is that rulers will no longer try to convert characters or provinces of faiths that have a matching Syncretism tenet, so for example Muslims will generally avoid trying to convert Sabians, because Sabianism has the Islamic Syncretism tenet. This is true for the following combinations:

Muslim faiths > Islamic Syncretism tenet
Christian faiths > Christian Syncretism tenet
Jewish faiths > Jewish Syncretism tenet
Dualist faiths > Gnosticism tenet
Eastern faiths > Eastern Syncretism tenet
Pagan faiths > Syncretic Folk Traditions tenet

Exceptions to this are if the ruler's faith is Fundamentalist, or the province being converted is a holy site.

I've also made it so that Jewish rulers are generally less likely to try to mass-convert vassals and provinces, as this is generally not plausible and the few examples we have of Jewish ruling dynasties (such as the Khazars and Beta Israel) seemingly did not force-convert those they ruled.

Exceptions to this are if the ruler's faith has the Mendicant Preachers tenet, or the province being converted is of an Israelite culture, is in the Holy Land (region), or is a holy site.

Finally, Eastern and Ecumenical faith rulers will generally avoid converting one another's rulers and provinces unless they have the Mendicant Preachers tenet, or the Communal identity tenet and the same cultural heritage as the province, or it's a holy site. For example, Jains and Buddhists should convert one another less zealously, and Orthodox rulers should be less aggressive in converting Apostolics. This doesn't affect non-Ecumenical Christian heresies.

I will monitor these changes and tweak as necessary, such as using game rules or other religious tenets as triggers.