Mini rugby also known as New Image Rugby is a form of rugby union designed to introduce the sport to children. It uses a smaller ball and pitch than standard rugby, and has nine players a side.
Invented in England in 1970, mini rugby was soon taken up by both the English RFU and the WRU.
The original game had four backs, and five forwards. There was no pushing in the scrum, which was made up of - two props, a hooker and a second row of two locks.
The International Rugby Board does not directly govern very junior levels of rugby but rather leaves local bodies to do things as they see fit. Consequently different countries have different junior versions of rugby designed to appeal to, and be safe for, younger children.
Technically, the RFU's regulations for age-grade rugby under the age of 13 are collectively known as "the rugby continuum", and "mini rugby" is just one of the stages of that continuum. However, "mini rugby" is much less of a mouthful and often used to refer to all age groups under the age of 13.