Unless means ‘if not’
Unless you pay for me I will not go to the cinema.
(Mejor dicho oralmente: Unless you pay for me I WON’T go to the cinema)
Real Madrid will win unless Messi scores
(Mas vulgo: Real Madrid’ll win unless Messi scores)
I hope this helps you (unless you knew it already, hahahaha!!!)
Peace and Love from the Maverick Team