Steppin' Razor is a hard Halo 3 multiplayer achievement. It is awarded for scoring a Triple Kill with the Energy Sword in a ranked free for all playlist. Unlocking this Achievement will give you the Ascetic Head piece for the Elite Armor Permutation, as well as five gamerpoints.
It is represented by a white circle with a red star on it. On top of this are three skulls and an Energy Sword.
A possible method to get this achievement is to get an Energy Sword on Crazy King on the level The Pit, and wait until two or more players are on the hill, lunge, kill them both and kill any other players entering the hill. Another possible technique is to stay at the top of the purple lifts in Construct. If the sword runs out of energy you may still beat opponents with the hilt to earn the achievement.
A great way to get it is in the playlist Living Dead on Halloween weekend. The playlist is ranked, and technically free-for-all, and zombies spawn with swords.
Another way to get this achievement is to play "Swords" on a relatively small map, such as The Pit or Guardian, since there is a greater chance that more people will be around the same area, aiding the difficulty of the four second time limit between each kill. You might want to melee with the B button, rather than lunging, because this will allow you to kill opponents faster. Many players in matchmaking don't bother to melee with the sword, instead they just lunge, meaning that their attack is slower. This is also a great way to get Overkill.
If you want to get three achievements in one game, you need to get an Overkill with the Energy Sword. This will get you the Triple Kill, Steppin' Razor, and Overkill which will give you all the Ascetic and Commando pieces. There are some situations where players got three kills with the sword and did not get the achievement. Be sure to stay alive after the third kill for awhile and you should get the achievement.
- This is principally a reference to the Reggae song of the same name by the Wailers, covered famously by Peter Tosh. Steppin' Razor is also a name given to a 'Street Samurai' character in the book "Neuromancer" by William Gibson.