I came across discrepancy of Mana income and Mana expenditures in that I have a total outgoing cost of (enchantments / titans / summons) = approximately 168. After setting my mana income to 169 - I end up with a mana income of -623.41...with no spells being cast.

After playing througha bit more I think what is happening the penalty associated with city numbers is being applied to the EXISTING mana pool.

I "tested" this by checking the mana income before and after battles in which I gained mana from world feature and found:
Battle #1 gained 303 mana - net change in mana income reported as -60.9 (60.9/303 = 20.1%)
Battle #2 gained 230 mana - net change in mana income reported as -45.8 (45.8/230 = 19.9%)

My current penalty for # of cities is reported at 20%. Perhaps that is just co-incidence.

Not sure if bug or intended.

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