The "Patent" is a 3 selection wager consisting of 7 bets: 3 singles, 3 doubles and a treble. This is a full cover bet that can be thought of as a Trixie with 3 single bets added to each selection.
Each choice appears in 1 single, 2 doubles and a treble. One losing selection can significantly impact the returns of this bet. Try out different outcomes and odds on the patent bet calculator to get a feel for how returns can be influenced by small changes. On the bet slip, the stake can be stated as either per bet or total amount; if per bet is chosen, the total stake will be 7 times the value entered.
Any one winning choice from the patent is enough to generate a return - this is considered to be one of the main advantages over a Trixie. A patent multiplies your original wager - so a €1/$1 patent cost €7/$7