A wedding scramble is a tradition, especially practised in the North of England and Scotland. It usually takes place as the bride leaves her home for the church. The father of the bride throws out a handful of coins (gathered for the purpose beforehand) from the window of the car to the children waiting in the street. The wedding scramble is one of the many good luck traditions of a wedding, alongside the lucky horseshoe and the bridal tradition of wearing 'something old, something new, something borrowed, something blue.'
Here is a real-life example of a wedding scramble from the 1960s.