There are a few different ways that a ticket with a scratched runner is handled, depending on the wager type and location.
Win / Place / Show; Quinella, Exacta, Trifecta, and Superfecta:
If it is a single race wager and the horse scratches, the bettor gets a refund once the race is declared official. If the exotic wager has more than one combination, and at least one is still valid, there will be a partial refund.
If the Scratch is in the first leg there is a refund for all combinations involving the scratched runner. If the scratch is in the second leg, after the start of the first leg, there is no refund, but if the winner was selected in the first leg there will be a consolation payout for the scratch in the second leg. If the scratch is in the second leg prior to the start of the first leg the combination with the scratched runner will be refunded. If the winner was not played in the first leg, it is a losing ticket with no refund.
In all states and Fort Erie except NY, KY, FL, CA, DE*, and WV, the post time favorite is substituted for the scratched runner.
In NY, KY, FL, CA, DE*, and WV there is a refund if the horse(s) scratches before the start of the first leg (once the final leg is declared official). If the horse(s) scratches after the start of the first leg, there will be a consolation payout. In NY, and DE this applies to thoroughbred tracks. Harness tracks substitute the post time favorite for scratched runners.
At Fair Grounds (in LA), they will refund the wager if the scratch is in the first leg and substitute the post-time favorite if the scratch was in a subsequent leg.
Pick 4, Pick 5, Pick 6, Place Pick All, and Grand Slam:
The post time favorite is substituted for the scratched runner.
*Delaware – Special Rules for False Starts
Delaware doesn't have a recall rule (in regards to a false starts.) Therefore; if the horse makes an attempt toward the gate and misses the start, it’s considered a runner and there is no refund to be issued.