Hogwarts has dozens, probably hundreds of suits of armour decorating its corridors. What I'm wondering is, why doesn't anyone in the Harry Potter series wear armour while fighting?
In the Muggle world, metal armour was rendered obsolete by firearms, but in the wizarding world, the advancement of spell "technology" (for lack of a better term) is slow or even static. I'd imagine that Avada Kedavra is a very old curse (older than the Latin spells) as it comes from Aramaic, so I can't really see how armour was made outdated by the introduction of some terrible spell, since the AK is pretty much already the deadliest curse around.
We also know that the Killing Curse and other spells are defeated by physical barriers. After all, they burst when they hit walls, and were deflected by the animated metal statues in the Ministry of Magic and Voldemort's shield in OotP. So, given that physical barriers stop deadly curses, why don't Aurors or Death Eaters wear magically-augmented metal armour? And if we take the hundreds of suits of armour in Hogwarts as evidence that wizards wore armour in the past, why don't they wear it in the present?
Tim the Enchanter