You have to start your game on the hardest difficulty and are not allowed to switch the difficulty setting throughout the entire game. Legend - beat the game on the hardest difficulty.If you fail to hack a device in the Sarif building or in any house in Detroit and Hengsha, this won't trigger any alarms and therefore won't lock the achievement Note: This is only the case in the areas where failing a hack can trigger the alarm. You fail a hack (the security 'detects' you).Laser emitter gets damaged from weapons and EMP grenades (this is different from camera - be sure not to use any EMP grenades on laser grids).Laser Grid gets triggered by the player or by an object.You destroy a camera by a weapon/explosion.Camera spots the player or a body (showing as Alarmed or Hostile permanently on radar - Suspicious is OK).A human enemy or a civilian activates an alarm panel.For more information on this achievement, visit the Deus Ex Wiki: Foxiest of the Hounds To check your progress on this achievement, be sure to check if you get the Smooth Operator XP bonus at the end of each mission (note, however, that this bonus available only on certain missions). Foxiest of the Hounds - beat the game without setting off any alarms.

For more information on the Ghost Bonus and detection details, visit the Deus Ex Wiki: Ghost (Bonus)

Being detected means: being spotted so that your radar turns red (not orange: really red), physically touching an enemy, letting enemies see other enemies bodies and/or turrets/bots exploding. Complete a mission without getting detected. More information on that below in the Hengsha 1 section WARNING: completing The Fall achievement (for the Rotten Business quest) locks out Pacifist.

Pacifist - complete the game without anyone dying by your hands (Boss fights do not count) YOU ARE NOT ALLOWED TO: Kill people by any means (weapons/mines/etc.), drop/push enemies off the rooftops, hide bodies in water (=in the canals in the sewers).

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