Perfection

Perfection is a medal awarded in Halo 3 Multiplayer for winning a Slayer game with at least 15 kills, and without dying or betraying a teammate. It should be noted that you do not need to get a Running Riot, just 15 kills, which means the medal can still be obtained if the game selects a new host and resets your spree. Also, if you are in a Team Slayer match, its still only you who has to get 15 kills and not die, but your team still has to win.

It is represented by a black hexagon outlined in silver/blue, which has another small blue hexagon in the middle. This medal can be obtained in any slayer-based game. One tactic is to camp and stay away from the enemies. When they advance stay out of sight then execute an ambush or assassinate. You can also try to perfect ranged attacks like sniping, or you can just play the game recklessly and hope you get 15 kills without dying. Camping and staying away from enemies can often result in lack of kills, but you are more likely to stay alive for the whole game, so a mix between camping and advancing is good strategy. Perfection is considered one of the hardest medals to achieve.

If the perfection medal is obtained in one of the Mythic Maps, then the Save This Film achievement will be obtained as well.