Blizzard has sent word that Diablo 3 will be going offline tomorrow at 2AM UK time to prepare the game for patch 1.0.3.
The studio anticipates that maintenance will conclude and that all services will be available at around 12PM. It also noted that players won't be prompted to download the patch until it is available in their appropriate region.
"If you are logging in from a European or Asian client, you will need to wait for this patch to release in that region before it can be installed," reads the official statement on Battle.net.
"Additionally, if your home region is the Americas, you will be unable to log into Europe or Asia using Global Play after patch 1.0.3 is live until those regions have also patched."
Patch 1.0.3 contains two main fixes, the first is to the drop rates which means "the best items in the game can drop from many different places, so a wider variety of play styles are viable." The second main fix is an adjustment to balance in the Inferno difficulty, which "creates smoother gameplay".
For extensive details on the patch, read Blizzard's own Diablo 3 Patch 1.0.3. design preview.