Jalil Abdullayev, works at KAIST
My favorite is pilum.
The roman javelin. It had very good design for an ancient army. The sharp end of pilum would bend after hitting target or ground. This would be good for two reasons. First, if it hit the enemy’s shield it would not be possible to remove it from the shield. Thus enemy must throw away his shield. A man without shield is effectively dead man. Second, even if it did not hit the target the enemy could not throw it back.