Bonus Draws are occasional draws introduced by the Operators to mark special occasions. The first three, for example, marked the name change from "National Lottery Main Draw" to "Lotto". The next was to mark the Queen's Golden Jubilee.
Bonus Draws are only drawn in association with, and after, a 'normal' Lotto draw on a Saturday or a Wednesday. They take the same format as a Lotto draw (6 balls chosen from 49 possible), except no bonus ball is drawn.
If you have bought a ticket for the 'normal' Lotto draw, the same numbers will automatically be entered into the Bonus Draw for you.
Bonus Draws are played for the Jackpot Only. That means you can only win a prize by matching all six main numbers. If you match three, four or five numbers, you win nothing.