Vidmaster Challenge: Classic

Vidmaster Challenge: Classic, just called Classic in Halo: The Master Chief Collection, is an achievement in Halo 3: ODST and is also one of the Vidmaster Challenges.

It is unlocked by completing any level solo on Legendary, while signed into Xbox LIVE, without firing a shot or throwing grenades. It is worth 25 Gamerscore in ODST and 20 in The Master Chief Collection.

It is represented by a green Marathon symbol, with two M7S SMGs and a skull, with the "peace" symbol printed on the skulls' forehead section.

Strategies and tips

 * The easiest level to do this on would be Uplift Reserve as you can just speed through most of it on a Type-32 Ghost. When you begin the level, get into the Warthog. Drive past the, Ghost, Type-25 Chopper and second Wraith, and pick up the Ghost (which you CAN boost) and replenish your health immediately after the second wraith. Drive your Ghost until the green-ish pond. Boost up the rocks on the opposite side of the pond to skip the three Shade Turrets and turn right and continue the mission. When you get to the next two turrets, just boost into them to break them and then just boost on to the end of the mission.
 * When in the Ghost, make the most of using the boost to climb rocks. You must skip fights whenever you can and focus on your achievement. Do NOT engage any enemy unless absolutely necessary.
 * You can also hijack one of the Brute Choppers at the beginning of the level by going around the rocks to the right, which is the easiest way to get past the first section.
 * Make the most of checkpoints as they will be important.
 * Make sure to replenish your health. There are 3 health locations easy to access without any enemies. 1: Small building just past the section with the first 2 Wraiths (where a fresh Ghost can be found) 2: In the tunnel, before you go out into the reserve (halfway through the level where the colonel is killed) 3: Just before you near the Covenant grav-lift pad.
 * You can still melee, assassinate, and splatter enemies.
 * A more methodical approach is to grab a Warthog and give the passenger in the gunner seat your Spartan Laser. Even if you do not see an enemy, listen for the laser to charge and let your marines kill all that they can from a safe distance. After every checkpoint, attempt to speed to the next one. If you cannot make it, let your marines do more damage before moving on.
 * If you lose the passenger with the Spartan Laser when exiting the tunnel to the landing zone, you can find marines in cover who can be armed with one of the rocket launchers or Spartan Lasers in the area.
 * The Chopper can be used in place of the Ghost, it may be easier this way as you can splatter Shade turrets and vehicles.
 * Another strategy is to make your way to the rock wall after you emerge from the beach, continue on this wall into you reach the path to the second wraith. A Chopper will drive and back up near this entrance which makes it an easy target for hijacking. Proceed past the second wraith and pick up the Ghost.
 * Players can earn two additional achievements at the same time: Deference of Darkness due to VISR being unnecessary in the daylight, Xenophobia for not using any Covenant weaponry.

Warnings

 * You need to be signed into Xbox LIVE to get this achievement.
 * Pressing down RT for ANY weapon/vehicle will count as firing. This includes briefly charging your Spartan Laser, even if you don't fire it, as well as honking the horn in a Warthog. In short, if the game registers you pressing the RT for any reason at all, end the game and start over again.
 * Boosting in a Ghost or Chopper does NOT count as throwing a grenade, therefore you may boost.

Trivia

 * This achievement is much like the Be Like Marty achievement, as the player is required to use what would be considered a "pacifist" strategy to gain both achievements. Both also include the "peace" sign in the representation of the achievements.
 * This achievement is similar to a challenge players completed in Marathon that spawned the name Vidmaster. This is likely the reason the challenge is named "Classic".
 * The requirements may state that one must complete ANY level solo on Legendary, but completing Prepare To Drop and Mombasa Streets solo on Legendary will not unlock the achievement.

External
Youtube: Rooster Teeth Achievement Hunter guide