With a total of 175 fixes and enhancements it’s by far the biggest ROME II update yet.
This update includes major AI improvements related to the constructions of new buildings, food supply management, creation of armies, technology researches and tactics used during battles, making the AI more organised and challenging. Further tweaks and improvements have been made to the diplomacy, missiles, melee units and much more.
The update is automatically applied to the game client upon restarting Steam and a full list of changes implemented is available here: http://wiki.totalwar.com/w/Total_War_ROME_II:_Patch_4
Patch 5 will enter public beta next week, with further technical optimisations and improvements to gameplay, balance and usability to come.
Assistance for anyone seeking to solve issues or improve the performance of ROME II on their system is available from the CA support team at http://www.totalwar.com/rome2support.
Answers to most-asked questions:
Should you make a start a new campaign?
To reap the full benefits of every patch, it is recommended to start a new campaign. However, please try your old campaign and see if you benefit from anything advantageous. If not, start up a new campaign and compare the differences/similarities. Your answer should lie there.
My game is broken after Patch 4, what happened Trish?
Try un-installing your mods if you have any installed. They may not be patch 4 compatible (please seek the mod provider for an answer to this) just yet. Then, try verifying your game cache. You can do this by going to your Steam Game Library, right-clicking ROME II, Properties, Local Files, then "verify the integrity of my game cache". This hopefully solves your issue. If not, please seek out: http://www.totalwar.com/rome2support
If I was in patch 4 beta, does this mean I have an update as well?
If you opted into the patch 4 beta and your version is #7573.461942 (you can see this on the top-right corner of your game) then you should already be all set!