Important Context (post-e1.5.5): The new "AI marriage" feature in vanilla is such a massively oversimplified system, to be kind, that I don't recommend it to anyone. Also, remember that "doing marriage" is just the beginning of Houses of Calradia.

Historical Context: Vanilla doesn't do AI-AI marriages. At all. No AI marries another AI beyond those scripted as already married at game start. Thus, by the third generation, clans start going extinct, and the world dies. Enter Houses of Calradia.

Features

• Arranges plausible marriages between AI nobles in an organic fashion
• Nobles are more likely to marry when their overall clan's fitness is low and, otherwise, are increasingly more likely to hold off
• If there are no eligible candidates for marriage, clans with low fitness levels may eventually choose to marry from the lesser nobility
• Matchmaking system is designed to avoid character bloat
• AI matchmaking only starts at age 27, so the player has plenty of potential spouses (configurable)
• If a clan leader is the only living adult in their clan and dies, then a distant relative will take their place
• Extensive set of configuration options, but only if you choose to install Mod Configuration Menu
• Built-in support for any custom calendars or aging rates which you may have defined with Pacemaker
• Can be freely added to an existing campaign
• Worry-free removal from a campaign with no special steps required
  

Compatibility

Houses of Calradia is extremely compatible.

• No external dependencies. However, if you'd like access to the in-game configuration menu, then you need to install Mod Configuration Menu.
• Worry-free addition and removal to and from existing savegames
• Only (soft) incompatibility would be with other mods which arrange marriages, but this would never result in a crash or incoherency
• Will even detect whether Pacemaker is loaded and adapt to any customized calendars / accelerated aging you're using
  

Future Work

If you have a savegame which has already been depopulated and add this mod to your campaign, then at this time, Houses of Calradia will only be able to prevent any further clan extinction and begin to rebuild the nobility: it does not yet have "immediate repopulation" functionality for repairing such vanilla campaigns. That is, however, a planned feature of the mod.

As I've developed a lot of statistics collection code to observe the long-term noble/clan population & its behavior with respect to Houses of Calradia, I intend to continue to expand upon this data to make tweaks and add new features, such as global population control, toward the end of improving matches, clan fitness (a predictor of how well a given clan is likely to do in terms of overall health in the future), potentially introducing new noble clans dynamically, and reducing any unnecessary character bloat.

Final Notes

If you appreciate Houses of Calradia, then please do remember to endorse it! Additionally, you might be interested in my other mods:

• Pacemaker, which gives you powerful, fine-grained control over the campaign timescale. If you use Pacemaker to increase the timescale, it is highly recommended to use Houses of Calradia.
• Noble Titles, which adds 4 ranks of gender- and culture-specific titles to rulers and their vassals -- a big bang for your immersion buck.
• QuickStart, which lets you go from 'New Campaign' to being on the map in 1 click -- great for power users, testers, and modders.
  

I am also a member of the BUTR (Bannerlord Unofficial Tools & Resources) Team, and I work primarily on ButterLib and related services within our team's swathe of significant offerings for modders and the community.

As with all of my projects, quality contributions and collaboration are very welcome, but even if you just want to browse the source code for Houses of Calradia, you may do so via its GitHub repository:

https://github.com/zijistark/HousesCalradia