Some mistakes that I have made in a couple games I have played lets see how big a list we can come up with .
1. leave your fishing boats unprotected and start a war and have all your cities starve.
2. have your only oil on the border with a friend civ there culture expands to absorp the oil tile in the middle of a war and then I can't build my tanks.

1. leave your fishing boats unprotected and start a war and have all your cities starve.
2. have your only oil on the border with a friend civ there culture expands to absorp the oil tile in the middle of a war and then I can't build my tanks.
