Guide
Lucky Stars, Thunderballs and other extra balls explained
What each game's extra number is, which pool it comes from and why it matters for matching.
By the LotteryUK editorial team. Published .
Why extra balls exist
Extra balls create more prize combinations from a single draw. They also change the odds of the top prize dramatically, which is why games with a separate extra pool can offer very large jackpots.
Separate pool or same pool
EuroMillions Lucky Stars, the Thunderball and the Set For Life Life Ball are drawn from their own, smaller pools. The same number can therefore appear as both a main number and an extra in one draw.
The UK Lotto Bonus Ball is drawn from the remaining main balls, so it can never duplicate a main number in the same draw.
International extras
EuroJackpot uses two Euro numbers, US Powerball a red Powerball, and Lotto 6aus49 a Superzahl that can be zero. 2by2 is unusual: it draws two red and two white balls, which we show as a main pair and a special pair.
Rules can change
Pool sizes have changed over the years for several games. Our draw pages store the structure each draw was validated against, so older draws are shown with the rules that applied when we recorded them.
