This perfectly round silver shield initially has a mirror finish. As a hero takes it into battle it remembers the enemies encountered, gaining a +1 to AC on any subsequent battle with creatures of that type. The events of the battle are intricately engraved onto the shield’s surface (which has a seemingly endless capacity for detail).
The bearer of the shield may also attempt to recount past battles (real or imagined) to the shield. Upon a DC 10 charisma check or DC 15 bluff check, the shield confers a +1 AC against the creatures described in the tall tales.
3 failed attempts at recounting stories cause the shield to be cleared of all of its memories. The engravings disappear. It reverts to its mirror finish. All bonuses are lost.