One thing I always felt was missing from Civ 4 was marshland. Reclamation of waterlogged areas has always been a major preoccupation for organised societies.
Marsh terrain would overlay grassland or tundra. It might contain oil, peat or some food resource - fish or maybe eels. 'Vanilla' marsh tiles would be unimprovable, would give very limited food and trade and would boost units' defences in much the same way as forest does now, possibly augmented by Guerrilla promotions.
You couldn't clear marshes outside your cultural borders and in any case not until, say, Civil Service. Even then it would be a major undertaking.
Possibly Marsh would influence city health much the same way as Jungle - not sure about this, maybe it should only apply to marshes in the tropics.
A new terrain type at this stage isn't without precedent - this was fixed for us in one of the expansions to Civ3.
Marsh terrain would overlay grassland or tundra. It might contain oil, peat or some food resource - fish or maybe eels. 'Vanilla' marsh tiles would be unimprovable, would give very limited food and trade and would boost units' defences in much the same way as forest does now, possibly augmented by Guerrilla promotions.
You couldn't clear marshes outside your cultural borders and in any case not until, say, Civil Service. Even then it would be a major undertaking.
Possibly Marsh would influence city health much the same way as Jungle - not sure about this, maybe it should only apply to marshes in the tropics.
A new terrain type at this stage isn't without precedent - this was fixed for us in one of the expansions to Civ3.