A parlay bet simply combines multiple wagers into one bet. It does this by rolling over the winnings from each individual wager into the next leg of the wager. Each leg or individual bet in the parlay must win for the parlay to grade as a winner.
A parlay bet involves combining multiple individual selections into a single wager. The main difference between a parlay bet and a straight bet is that all of your selections must win for your parlay bet to cash. A single losing individual pick means the entire parlay bet results in a loss.