A funny mix-up happened regarding the launch of Treyarch's Call of Duty: Black Ops 2. It would appear that some gamers who purchased the hard copy PC version of the game received a second disc that contained code for EA's Mass Effect 2. This means the players who purchased these defective copies couldn't finish the install since the client required use of the second disc.

Goes to show than human error is definitely a possibility in manufacturing. It's interesting because the discs still have the intended "Black Ops II" cover on it but has information for Mass Effect. Also a coincidence that they're both the second installment of their franchise. What makes this funny, to me at least, is the fact that EA and Activision are huge rivals. It's a comedic shame that the mix-up wasn't between code for Battlefield 3. That would have been awesome.

Of course, none of this, I presume, was intentional and was likely an error caused by the manufacturer of the discs. But look on the bright side, if you buy half of Black Ops 2, you get Mass Effect 2, or a part of it, for free.