Elder Futhark
Thurisaz is the giant and the thorn, and the Anglo-Saxon poem is exact about the second: sharp to every thane, evil to grasp, cruel to anyone who rests among them. The rune is a force that works and injures whoever handles it carelessly. Something today has that shape: a defence, a boundary, a piece of necessary sharpness. Use it and do not lean on it. The thorn does its job by being where it is, not by being held in the hand.