Rugby shirts need to be able to take lots of heavy tugging and pulling.
They also need to be lightweight, comfortable and strong - all at the same time.
Traditionally, jerseys were made from cotton, which would often get very heavy if it was raining.
But technology has seen lots of new lightweight water-resistant, synthetic fibres in modern jerseys.
Although your rugby team/school will provide your jerseys for competitive matches, it is worth buying one for training.
Make sure you get the right fit - too small and it will rip, too big and it will affect your performance.