Vidmaster Challenge: Déjà Vu

Deja Vu is an achievement in Halo 3: ODST and one of the Vidmaster challenges. It is unlocked when you complete Highway on 4-player Legendary Live co-op, with Iron skull activated, and not using the Warthog or Scorpion at all. It is worth 25 Gamerpoints. The achievement is likely named due to its similarity to the previous Vidmaster Challenge achievement Annual, which also requires the Iron Skull and 4 player Legendary live co-op play.