Okay so here is a bit of a doozey. I just finished a 2 hour attempt of the achievement “Who Needs Them?” which is to complete the Ark in Halo 3 on legendary without stepping foot in a vehicle. I can assure you that the difficulty was on legendary but once I had completed the mission I got no achievement pop. I looked to the achievement menu and it was still locked. I would have known if I had got in a vehicle so I am curious as to how it has not unlocked. The only time I even touched a vehicle is boarding wraiths to destroy them, which is kinda required as heavy weapons are scarce in areas that are designed for tanks. Any advice would be greatly appreciated.
I hate to break it to you friend, but boarding those Wraiths to destroy them was exactly what negated the achievement for you at that point… Don’t fret though, as there is a much easier method to complete this achievement. Load up The Ark on Legendary with the Iron skull turned on, and play through the level as you normally would. You can enter vehicles such as the Scorpion tank, Warthog, Chopper, etc. Any time you die just immediately hit start and quit to main menu to negate the effect of the Iron skull, and then load up the level again. When you’re at the end of the level, there aren’t any vehicles at that point so just die at one of the final checkpoints, immediately pause and quit, then load it up again, and the game will still register the Iron skull and think you never entered a vehicle at all (even though you did) and will grant you the achievement. I know it may sound confusing and yes, it is a “cheat” to get this achievement, but it 100% works. Hope this helps 
> 2533274812864671;2:
> I hate to break it to you friend, but boarding those Wraiths to destroy them was exactly what negated the achievement for you at that point… Don’t fret though, as there is a much easier method to complete this achievement. Load up The Ark on Legendary with the Iron skull turned on, and play through the level as you normally would. You can enter vehicles such as the Scorpion tank, Warthog, Chopper, etc. Any time you die just immediately hit start and quit to main menu to negate the effect of the Iron skull, and then load up the level again. When you’re at the end of the level, there aren’t any vehicles at that point so just die at one of the final checkpoints, immediately pause and quit, then load it up again, and the game will still register the Iron skull and think you never entered a vehicle at all (even though you did) and will grant you the achievement. I know it may sound confusing and yes, it is a “cheat” to get this achievement, but it 100% works. Hope this helps
Do you actually have to use the iron skull? Also thanks for the advice, kinda dumb that boarding breaks the achievement.
Yes the Iron skull is required. Otherwise if you use vehicles and complete the level, the game will register that and you won’t unlock the achievement. Just make sure if you die anytime immediately pause the game, save and quit and then load up the level again. As long as you exit the game before you respawn, the Iron skull won’t kick in and you’ll be at your last checkpoint, instead of at the beginning of the level. And then make sure towards the end of the level after all the vehicle sections to die at one of the final checkpoints and do the save and quit method, and the game will register Iron and it will
be as if you started the level at that last checkpoint, and you won’t have to enter any more vehicles. Complete mission, achievement will pop.
And I agree, the achievement being negated from
boarding vehicles is pretty silly. I’m also pretty sure if you even use a stationary turret at any point that negates it as well. Either way, with the Iron skull method, you don’t have to worry about that since you can use any vehicle you want at that point
> 2533274812864671;4:
> Yes the Iron skull is required. Otherwise if you use vehicles and complete the level, the game will register that and you won’t unlock the achievement. Just make sure if you die anytime immediately pause the game, save and quit and then load up the level again. As long as you exit the game before you respawn, the Iron skull won’t kick in and you’ll be at your last checkpoint, instead of at the beginning of the level. And then make sure towards the end of the level after all the vehicle sections to die at one of the final checkpoints and do the save and quit method, and the game will register Iron and it will
> be as if you started the level at that last checkpoint, and you won’t have to enter any more vehicles. Complete mission, achievement will pop.
>
> And I agree, the achievement being negated from
> boarding vehicles is pretty silly. I’m also pretty sure if you even use a stationary turret at any point that negates it as well. Either way, with the Iron skull method, you don’t have to worry about that since you can use any vehicle you want at that point
Thank you so much!