Happiness is a grassland Remnants of Patria in your starting cross.
So I had an idea while playing tonight. Two actually. The first is to change the terrain preferred by the Legion to Haunted Lands instead of desert. The second is, I think, better but considerably more complex.
Add a new feature for scorched lands. Ideally two will be needed. Whenever a terrain is scorched it will change terrain type temporarily.
Grassland -> Scorched Lands -> Plains
Plains -> Scorched Lands -> Desert
Forest/Jungle Grassland -> Burnt Lands -> Plains
Forest/Jungle Plains -> Burnt Lands -> Desert
Desert/Scrub Desert -> Scorched Lands -> Desert
Snow, Tundra and Marsh will be (conveniently) unaffected since scorching these lands is more about melting/evaporating water instead of burning flora. The transformation can be random much in the way the Riverside Desert -> Floodplains is done with setTempFeatureType().
Fire in tiles can also temporarily add a scorched feature type, allowing for a fire in your city plots to have a lasting effect on your economy even after they are extinguished.
Of course inside the Legion borders, the Scorched Land features never revert to the normal land types. The various scorched features will have negative yields to completely offset the terrains they are on. These negative yields will not apply to the Legion since they don't really care if their land is a wasteland.
And of course, since all their lands aren't desert, the burning sand problem is moot.
This has some other effects on the game:
* "Terraforming" is a bit slower of a process and has a temporary downside before you get the land you want. This probably effects Malakim+ the most. Recovery from forest/jungle clearing will also be slower.
* Fires have a greater visual impact and do considerably more damage. You might even be able to hurt someone's economy by continually scorching their lands.
This also opens up some possibilities:
* New creation/nature spells to restore scorched lands?
* Burning Horsemen! Have the Horsemen and the Avatar burn the lands they pass through.
* Fear the Volcano! Forget the wimpy volcano event. Now when a volcano appears it scorches all adjacent tiles! Pass the solarcaine.
* Bring back the burning fireballs! Be careful when casting fire elementals, they might just burn a plot to the ground. With scorching this can be done without actually setting the plot on fire.
* Some units might like a scorched earth and could get bonuses when attacking or defending from it.
Time to get some dinner. Let me know what you think, I might have time to work on this at the end of this week.