Trifecta betting challenges you to pick the first three runners in the correct order in a race. You will need to pick at least three runners in order to make a valid Trifecta bet.
Once you have picked your runners, you then must decide which order they will finish in - to take the guesswork out of doing this many people choose to "Box" their runners "all ways", meaning that they buy all of the possible ways that their picks can finish 1st, 2nd and 3rd. These "Boxed Trifectas" start with 3 runners where it takes 6 bets to cover them all ways, then 24 bets to cover 4 runners and so on. Boxed Trifectas are very easy to place and can be done on a single ticket. Boxed Trifectas work very well with Percentage Betting so you may want to read up on that too.
Minimum field size for Trifecta betting: There needs to be at least three runners left in a race for a Trifecta bet to remain valid. If there are less than three runners all Trifecta bets will be refunded.
Minimum Bet: The minimum amount for a Trifecta bet is $1.
Scratchings: If one of the picks in your Trifecta bet is scratched (withdrawn) from a race a Trifecta permutation that included the scratching will be refunded when the race is resulted.
Dead Heat: Should there be a dead heat for 1st, 2nd or 3rd place in a race, Trifecta dividends will be declared for each valid permuation of 1st, 2nd and 3rd - these dividends will be half of what they would have been without the Dead Heat e.g. if there was a Dead heat for first between runners 1 and 2 with runner 3 third, then Trifecta dividends would be paid for both 1-2-3 and 2-1-3.
Abandonment: Any Trifecta bet made on a race that is later Abandoned will be refunded.
Roving Banker Trifecta: A Roving Banker "RB" Trifecta is a strategy for placing a Trifecta bet where you choose your runners for a Trifecta bet as normal and then single out one of them to be your RB. The RB Trifecta bet comes out on three separate tickets: one ticket with your RB for 1st and your other runners for 2nd and 3rd, one with your RB to come 2nd with your other runners for 1st and 3rd, and one with your RB to come 3rd with your other runners for 1st and 2nd.
A RB Trifecta can cost much less than taking all of your runners in a Box Trifecta.