Tom Clancy's Splinter Cell: Double Agent

Simply complete one of the two training missions. You will find these training missions located in the solo menu.
Mission 1
Easily done, after the running through the dark and avoiding the lights, you will come upon a white room with cameras and lasers. Just walk through them and grab the photo.Even though you directly disobey the voices in your head, a door will still appera and you have finished mission number one.
Mission 2
Also extremely easy, just follow the guard through various doors and rooms and you can even kill him. Then look for two big double doors that are white and go through. You will then come upon a white maze with two terrorists. Just go towards the left side looking for the correct path before leaving and kill the terrorists.A door will appear, climb the staircase towards your achievement.