A protective helmet to be worn by a player engaged in a sport comprises a flexible outer shell and a multi-layer liner assembly disposed within the outer shell. The multi-layer liner assembly includes an inner-layer, a middle-layer and an outer-layer, and permits relative rotational movement between said layers when the helmet is worn by the player and receives an impact. The inner-layer is made from a first material with a first density and is mechanically coupled to the outer-layer without adhesive. The outer-layer is made from a second material with a second density that is greater than the first density of the inner-layer. The middle-layer is made from a third material that has a third density that is greater than the first density. The outer-layer also has a thickness that is greater than a thickness of the inner-layer and varies between a front region of the outer-layer and a crown region of the outer-layer.