- Clear All Missions (including Side Ops and Extra Ops) With an S-Ranking.

Getting an S-Rank is all about earning points during the missions. You get bonus points for not killing any enemies, no continues, no retries, no alerts and no combat reflexes. Although, you dont always need to complete every single one of those. It is still possible to earn an S-Rank if you need to retry a checkpoint or get a kill. If you do lose any of those bonuses youll need to beat the mission quickly and extract prisoners to make up for the lost points. The more kills, alerts or continues you use, the more points youll lose. Extracting prisoners will also give bonus points. The time it takes you to complete a mission also plays a factor. The faster you can beat a mission, the more points youll earn from the time bonus. These can be done on Normal difficulty.

If you need to take an enemy out, use the Silent Pistol. When aiming, press R1 to enter first person. This will make it easier to get headshots and not waste your ammo.