Hidden and Dangerous
Complete a campaign mission without being seen
Mission 4 – Fort Rifugio
– You can load up your last savegame if you get spotted. Make manual saves often to speed it up.
– Only a full red circle counts as beein spotted. If they see you and it’s building up to yellow or red you’re still good.
The first parts are fairly easy since the enemies behave mostly the same on their routes. After getting the key and freeing the prisoner you will have to take out all enemies at the front gate. It can be a little tricky because they move more unpredictable and sometimes run arround when they’re alerted to yellow. Don’t forget to pick up the extra ammo and make a savegame after that.
After you cleared the gate you have to provide cover with your sniper rifle. This part doesn’t have any effect on the achievement/trophy anymore. The sirens are constantly ringing so you can fire away.