What is the shape of a rugby ball?

The shape of a rugby ball is oval, more precisely a prolate spheroid or elongated ellipsoid.

The ball’s unusual form developed from early footballs made with leather casings and inflatable animal bladders. Pig bladders varied in shape and size, giving early balls an imperfect, sometimes nearly spherical or plum-like profile. In the 19th century, rubber bladders made inflation easier and encouraged a more pronounced egg shape.

The oval ball suits rugby’s handling-based style: players can carry it securely, pass it sideways or backward, and kick it unpredictably when it bounces. The shape is sometimes confused with an American football, but rugby balls are generally rounder and less pointed. Modern rugby balls are usually synthetic, waterproof and made from four panels. In rugby union, the regulation ball is roughly 28–30 centimetres long.