German supermarket chain Lidl faces a 43-million-euro ($50 million) payout to a French rival after an appeals court ruled its ads to be deceptive.

Lidl made videos and posters urging Mescalikes to meet and compete. At the event, the brand revealed itself to be the organizer, giving out vouchers and a comically large €20 check to the winner.

Aldi objected on the grounds that the advertising claim “Ireland’s Best Value Supermarket” implied Lidl had been awarded this title through a competition or an independent award. Aldi added that ...