The Xbox One's connection to the cloud can alter a game's Achievements in response to player behavior, Microsoft has revealed at its ongoing unveiling event in Redmond. Dan Greenawalt, Creative Director at Forza developer Turn 10 Studios, cited the "I took an arrow to the knee" meme as an example of how game makers might hinge their extrinsic rewards on post-launch reactions.
The meme began with The Elder Scrolls 5: Skyrim, in which droves of melancholic guards told the same story about an old injury.
To extrapolate from Greenawalt's comment, it seems Microsoft is keen to further distance itself from the idea of the game as a static disc. Xbox 360 games had their Achievement lists extended with significant title updates and downloadable expansions, but the Xbox One is expected to update the rewards list more fluidly. Game creators may use Achievements to encourage comical or topical behavior, or use them to educate players if they're missing certain features or secrets.