Tom Clancy's Splinter Cell: Pandora Tomorrow HD

At any given time if you press , Sam will whistle and if there are any guards or civilians nearby they will go and investigate the exact to where the whistling came from. The music will change also. Whilst they investigate, go behind them and knock them out by pressing . Whilst your opponent investigates, you have to strike before the music ends, if you take too long and your victim just walks off then your chance is gone and you will therefore have to whistle again. You are going to need to do this 50 times and the trophy will pop. Furthermore your stats will carry over to your next playthrough so if you get 30 in your first runthrough, then it will carry over if you choose to start a new one.

Tip: You will find a lot of opponents throughout the game are just stood stationary with their backs turned against you. Good tactic is just to casually go up behind them and quick whistle and then knockout. However, you have got to be quick in doing so otherwise your cover will be blown.