Finally I can say the Decision Mods feature is done (for now). I ran the simulation multiple times this last weekend and found a bunch of new bugs that I managed to fix before Sundays' end of day. There might be (and possibly are) a bunch of nasty bugs hidden still. Nevertheless I hope to catch those along the way when I convert the rest of the hardcoded decisions in the coming months.

I also started updating the modding guide, since it will be essential for people who try to create mods using the new system. I wish to finish the mod guide soon, yet doing that isn't a high priority. In that regard, I'll be spending just a couple of hours each week updating it while also working on the next feature for 0.3.4.

This brings up the topic of the next feature I'll be working on: Tribal Migrations.

So, Tribal Migrations, is the feature where I try fix/improve on the old feature of group migrations. This is the behavior that pushes human groups to expand and claim new lands during the initial stages of the simulation. Each cell group is incentivized to split and move part of its population to adjacent cells that are empty or less occupied than their own. This incentive is greater if the cell cannot support a larger population than it currently has, and adjacent cells look capable of supporting the growing population.

The problem with the current group migration algorithm is that it barely takes into account any influence from any tribe the group might be part of. Additionally, groups tend to stop migrating once all adjacent terrain cells seem to be filled. Tribes themselves grow by increasing their prominence over cells adjacent to their territory. But this is an ad-hoc solution that is not modeled around any realistic behavior. It also pretty much stops once a tribe finds itself surrounded by other tribes.

The idea for this feature is to model tribe-wide migration behavior on which groups under the influence of a tribe will try to migrate toward free and occupied cells that match preference criteria for the tribe, and out of cells that do not match that criteria. The criteria used can range from preference for certain biomes, filling up regions, maximizing activity productivity, etc. And it will change over time to accommodate changes in preferences and activities for a tribe while also taking into account the relationship status with neighboring tribes.

The first thing I want to work with next week is with region occupancy. Which will make tribes try to fully cover regions before expanding to other areas. Hopefully I can get some interesting behavior to showcase in a couple of weeks.