• Unless you purchased the Collector’s Edition of the game you will have to unlock this via Ubisofts UPlay service. It’s easy enough to do by simply playing the storyline a bit or if you still happen to have points left over from Assassin’s Creed II.
This game mode is more suited towards those hardcore players who think that sneaking your way 100% through a stage is what it really takes to be a Splinter Cell. Whereas Hunter is about killing the enemies while remaining undetected as much as possible Infiltration is totally about evading the enemy soldiers. You’re going to have to eliminate them but you cannot afford to be seen. Rather than calling in reinforcements like Hunter mode does you will simply lose the match if you’re spotted. This makes this mode incredibly hard, and strictly for those who are looking for a challenge.
Above: Lure them in but make sure they don't alert the others.
Now most of the strategies that work for Hunter mode will also work for Infiltration mode. The main difference is that you cannot bring in any of the noise makers. Don’t even bother with bringing any weapons that don’t have silencers, just in case you accidentally fire them. It’s heavily suggested that you avoid using Flash bangs or EMP grenades as well, since that can cause the enemies to go on high alert and they’ll immediately radio for support at the first sight of you which is a game over.
There isn’t really all that much to be said about this mode since it’s basically just a revamped version of Hunter. The last thing is to make sure you only take action if you’re 100% sure you won’t be caught for it. Don’t shoot at enemies if you might miss, don’t rush an enemy for melee attacks if you think he might move and don’t slack off. A game over can happen very suddenly in this mode.