Regarding point #3 (from my previous message), here are some figures (as I see them): Since Dimension Door and Mana Regeneration should be interchangeable spells, the regeneration on the Expert level (presumably Water) should restore more Mana than would be spent if the player walked instead of using Dimension Door. Since Dimension Door allows you to jump over mountains/obstacles/chasms (in the Underworld), Mana Regeneration should also have some kind of boost compared to Dimension Door (or be level 4 instead of 5). Of course, on the other hand, with Mana Regeneration, you can visit more places and clear more guards, but this doesn't seem like such a big advantage, especially in the late game. I was considering a hero with maximum upgrades, an Expert Water skill, an Expert Air skill, no specialization in logistics, wearing gloves and boots. The maximum Mana reserve in the morning is 3500. With Dimension Door, we spend 200 Mana and fly (at most) 8 cells diagonally and 1 cell straight. Without a penalty, this is 1228 Mana, and with the maximum penalty (swamp), it's 2151 Mana. If we take the maximum penalty, then, in order for Mana Regeneration to match Dimension Door in terms of movement, it needs to restore 1951 Mana. But we want Mana Regeneration to provide more restoration, so that it is more comparable to Dimension Door in value. I think this figure should be 60-70% regeneration at the Expert Water level (presumably), which is 2100-2450 Mana. Perhaps it would be fairer to scale these figures not from the maximum penalty, but from a 150% penalty, which would result in about 50% regeneration, and then the option of 15/25/40/50 would look good. Thus, Dimension Door and Mana Regeneration can become interchangeable, and bringing them under a common denominator of "no more than one of these spells per day, on XL+U with Expert Water/Air, no more than two in any combination" would be justified and fair.