A dead heat is essentially when there is no clear winner and a tie occurs between two, three, or more competitors. So if there are two winners who tied then the stake would be halved and settled at the odds at bet placement. If three winners tied then the stake would be split by three and settled at the odds.
For example – two teams tie for first place. You have placed 10 at 2/1. In this case you would receive 5 at 2/1.