6. When The Full Stealth Approach Doesn't Work, Murdering Everyone Does
Let's be honest, we're not perfect stealth professionals. Even if Miller reminds us that we are on a stealth mission, sometimes things don't go according to plan. An enemy soldier does a complete 180 turn, JUST as you're about to grab him, and sets off the alarm. There's nothing else to do now, as your tranq gun won't have the immediate effect that you're required to stop everyone coming after you. Therefore, there's only one thing to do: kill every soldier, until the alarm stops going off. You really didn't want it to end this way, but you've just got to commit now. In MGS V you could salvage things a tad by tranquillising a couple of soldiers in case they have good stats to be sent to Mother Base, but every other game saw you ventilating everyone in the vicinity before continuing if need be.