Combine legs into one price and payout, with an honest note on the stacked cut.

A parlay only pays if every leg wins. The combined price is each leg's decimal price multiplied together, and the payout grows fast because the chance of all of them landing shrinks fast.

The catch is that the book's cut is taken on every leg and then stacked. A two-leg parlay carries roughly twice the cut of one bet, a three-leg parlay roughly three times, and so on. That is why parlays are the most profitable bet for the book and the most expensive for you.

Multiplying the legs only gives a true chance when the legs are unrelated. Legs from the same game move together, so a same-game parlay's real chance is not the simple product, and its price is usually worse than it looks.