Do more lines improve your odds? The maths of playing several

Does playing more lines raise your chance of winning?

Yes, in direct proportion, and only if the lines are different. Each distinct line is one more combination out of the same total. In a game with 139,838,160 possible outcomes, such as the EuroMillions jackpot, one line wins in 139,838,160 draws on average and ten different lines win in 13,983,816.

That is ten times the chance of a very small chance. It is still far smaller than one in a million.

What happens if two lines are identical?

Nothing useful for your chance of winning. Two identical lines win together or lose together, so the chance is the same as with one line. If they do win, they pay twice. You have paid for the same result twice.

Does it improve what you can expect to get back?

No. A fixed-odds line pays a published multiple of its price, and that multiple is set below the true odds. Every line carries the same margin, so ten lines cost ten times as much and are expected to lose ten times as much in the long run. More lines buy a higher chance of some win in a given draw, not a better return.

The shape of the result changes too. With more lines a small prize on at least one of them becomes more likely, while the total you stake rises with every line.

How many lines should you play?

As many as you are comfortable paying for as entertainment, and no more. Decide the total for the draw before you play, divide it by the line price, and stop there. Playing extra lines to recover an earlier loss does not work: each draw is independent, so the next one owes you nothing.

If gambling stops being fun, the responsible gambling page explains how to set limits or take a break.