A protective headgear includes, for example, a headgear body that is wearable on a head of the wearer having a top slot in a top portion of the headgear body, wherein the top slot runs from a front portion of the headgear body that covers a forehead of the wearer to a back portion of the headgear body that covers a back of the head of the wearer. A top piece slidably attaches to the headgear body to cover the top slot, wherein the top piece diffuses energy from an impact to the protective headgear by sliding within the top slot. Other embodiments are disclosed.