by KingofTown
Correct. Most of these rules are thematic. I've found it easier to think of them this way rather than just "random rules to make things more complicated".Your units will not do foolish or 'immoral' things with you (entering scary tombs, burning down a monastery, etc).
The reason gold mana does not work at night is because it gets its power from the sun. In a dungeon or tomb, the sun is not visible...thus, the gold mana has no effect. Likewise, dark mana can only exist where there is no sun...and can be used in these dark places.
Dark mana
At night, it is harder to see. In forests, it's almost impossible to see (increased move cost). Even when near a mage tower or keep...it is hard to see what lurks behind the walls.
In the day, the desert is frickin HOT (increased move cost).
Rampaging enemies are always revealed because the locals are aware of these menaces and tell stories of them (hence the +reputation for killing them).
Cities have a lot of lights...thus it is easy to see who lurks behind the walls when near, even at night.
When reading the rule book, try to come up with a reason why these rules are this way. It will help you not forget them when playing...and it will make it easier to explain to new players.
New Player: "I want to burn down this monastery"
Me: "You only have 2 cards in hand. Your units aren't going to help you"
New Player: "Why not? That's a stupid rule"
Me: "Because you are about to kill a bunch of innocent monks in hopes of stealing their treasure. They are loyal...but not stupid."