It's just a flesh wound
Less than a week after its release, Total War: Rome II is getting its first patch on Friday. This will be aimed at fixing bugs and crashes, as well as some gameplay balancing tweaks.
Patch notes aren't currently available, but Creative Assembly has said the patch will be aimed at fixing issues that have come up from the wide range of hardware people play the game with. The studio is also tracking gameplay results and will be making small adjustments to game balance.
If you are having any weird issues or crashes, there is a lot of helpful information and fixes over on the Total War forums. I'm really excited to jump into this soon, as I've been hearing lots of awesome things about the game.