There are severaal vidmaster challenges in both Halo 3 and Halo 3 Odst. By completing them all, you recieve the recon armor in halo 3. You will get 0 gamerscore in halo 3, but 25 gamerscore in halo odst, per achievement. Halo 3 Vidmaster Challenge: 7 on 7 To get this , enter any ranked or social match with seven experience, on the seventh of the month. Very simple. Vidmaster Challenge: Lightswitch Become a Lieutenant online. Vidmaster Challenge: Annual Complete Halo (the level) on Live, with iron on, and playing on 4 player legendary while everyone is in ghosts. To do this beat guilty spark, and go outside, near the ramp that is to your left when you exit are four ghosts. Please note that you must first go down the ramp to find them.Then continue on like on normally would without the warthog. Halo 3 Odst Vidmaster Challenge: Deja Vu Complete Coastal Highway on live coop legendary with 4 players and iron on. You may not use any warthog or tanks. Vidmaster Challenge: Endure Pass the fourth set on heroic firefight on four player live. Vidmaster Challenge: Classic Pass an entire level on live legendary, solo campaign with no shots fired/ grenades placed or thrown. Easiest way to do this is on uplift reserve, take back the hog or take over a ghost and keep on driving, melee is aloud.