A Trifecta consists of selecting three runners to place first, second and third in the correct order. You can select as many runners as you want and make it a boxed Trifecta, or also pick a standout for any of the 3 positions.
Trifecta:
Trifecta bets require the selections to finish in 1st, 2nd and 3rd place, in correct order, to be successful.
Boxed Trifecta:
Boxed Trifecta bets require any of the selections to finish in 1st, 2nd and 3rd place, in correct order, to be successful.
If a selected runner is declared a "non-runner" or scratched after the wager is confirmed, wagers will be refunded on every combination which includes the scratched runner and the combination stands and the wager re-calculated without the scratched runner.