About the fall patch...

[DefiledNH]

Will it screw up my current save games? As in, can I still play them after the patch?

 

[Tinker]

Yes, you can still play your old saves, although if you took any policies or civs that changed, they'll have changed as well.

 

[joncnunn]

This was actually a reason I signed up for the Beta when it became available before I started the next game. (Second version that started on or around Oct 4 as I had a pre existing game all during the first beta)

But biggest side effects are if you were extremely close to a diplomatic or space race victory before the patch as the requirements for a Diplomatic victory increased and you now need 2X more hammers and gold for space ship parts.

Additional side effect: If you had actively pledged to protect and were at or slightly above the minimum resting point, over the next few turns, it will drift down to the new 5 points lower resting point.

And AI active settlers may change routes and the AI could decide to go on a science building spree to catch up with new higher science flavor.