Pacifist Achievement in Halo: The Master Chief Collection

Although this achievement sounds intimidating, this ten minute mission can easily be completed under such constraints when playing on the Easy difficultly setting. Take note that it has been reported to not unlock during Co-Op play, so it's best to perform it on your own.

As soon as the mission starts, turn to your left and head down the beach until you reach the overturned Warthog. From here, proceed up the hill to your right, leading you deeper into the island and eventually into the security room of an underground complex. After disengaging the control room's security mechanism, exit the complex, grab the overshield on the ground to your right, and drop down the cliff onto the beach. Hope inside the nearby Warthog and drive back to the map room's entrance.

Once there, you'll need to reach the bottom level of the facility and activate the cartographer before you're demanded to return topside. When you finally reach the top floor, push past the Elite wielding the Energy Sword, Hunter duo, and Stealth Elites. Now wait until the Pelican lands on the platform and when it does, get inside and the mission will end. If you managed to survive the mission without shooting, using grenades, melee attacking, dying, or restarting, the achievement will unlock.