Rugby shirts need to be able to take plenty of 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 new lightweight water-resistant, synthetic fibres in modern jerseys.
Although your rugby team/school will provide your jerseys for matches, it is worth buying one for training.
Make sure you get the right fit - too small and it will rip, too big and your opponents will be able to tackle you more easily.
Many shirts at the top level are designed to be figure-hugging. They are lighter and are designed to snap back once someone tries to grab them.
There are also different designs for the forwards in the scrum and the backs or loose forwards.
The five forwards in the scrum wear shirts that have panels for their team-mates to grab onto.