Fable II, scheduled to ship to retail stores on Oct. 21, will not include online co-op functionality right out of the box and will require a downloadable update afterward, according to a post on Microsoft’s Gamerscore blog this afternoon.

Offline co-op will work on day one, but Lionhead and Microsoft Game Studios are still hammering out the kinks in the online co-op. According to the post, the game’s developers are "looking to get the update out within the first week of launch in North America." As of today, there’s no specific date set for the patch, and there’s no word on when other regions might see the update.

Although you won’t be able to join up with a friend right away online, the Gamerscore post says you’ll "still see your friends as glowing orbs as well as chat and trade with them."

Fable II boasts an ambitious co-op mode that allows you and a friend to interact and affect one another’s game worlds to a large degree. And although we’ve previewed theoffline co-op, we haven’t yet seen the online functionality in action.