Version 6.3

• Quarries are a pollution source.
• Unimproved coal, oil, and uranium yield science instead of production.
• Iron, aluminum, coal, and uranium mines; and oil wells and offshore oil rigs, provide bonus production equal to their science yield.
• No longer requires Rise and Fall.

Version 6.2

• Niter and salt mines are no longer affected by pollution (they still produce it).
• Oil wells and offshore oil rigs produce pollution.
• Researching Cultural Heritage reduces the pollution penalty to food yields.

Version 6.1

First release for Civilization 6.