South Park: The Stick of Truth - No Child Left Behind Achievement

Achievement - No Child Left Behind
Complete the game without ever ending a combat with a buddy knocked out.
**This is a Missable Achievement **

As the achievement says, throughout your entire playthrough, you must never finish a battle while a buddy is knocked out. If your buddy does get knocked out, you CAN revive him, just so long as the battle doesn't end while he is knocked out. As soon as you beat the final boss this achievement will unlock. I recommend making continual manual saves throughout your playthrough in case you walk into a battle you can't handle. If you do accidentally end a battle with a buddy knocked out, reload a previous save/checkpoint to avoid missing the achievement. Also remember that you can lower the difficulty in the Options menu at any time without affecting any of the achievements.

An important general combat tip: if you initiate a random fight (swing your weapon at the enemy to start a battle), this means you get to attack first! If the enemy comes up to you and strikes you to start combat, they get to attack first. So make sure you initiate the battles as often as possible, letting you attack first so you have the upper hand.