Getting more popular in video games today, an achievement is a feat that the game records and displays for others to see that you have accomplished such a task. They are usually rewarded with points that have no real value other than to enlarge one's e-peen. Achievements were originally started by Xbox 360 Live. Other games like World of Warcraft have taken on this addition as well.
"Dude check out this achievement I just got for falling 30 feet off this cliff and dying!"