Check out the link below to access the bulk of the download for 1.3.1!

The Invasion draws closer as we release the 1.3.1 Pre Patch. Be prepared to assault you enemies cities and defend your homelands early by downloading the 1.3.1 Pre Patcher.
Players can now get a jump start on Game Update 1.3.1 by downloading the bulk of the update here.
Clicking the link above will prompt the file PrePatch1.31Setup.exe, which is a single 750 MB download. Simply install the file and continue to play the game as normal. The file will automatically be activated with the release of Game Update 1.3.1 That's all there is to it!

Please note: This pre patcher is for North American and Oceanic clients only. The GOA team will be launching our European pre patcher early next week.