Other types of betting

One can also bet with another person that a statement is true or false, or that a specified event will happen (a "back bet") or will not happen (a "lay bet") within a specified time. This occurs in particular when two people have opposing but strongly-held views on truth or events. Not only do the parties hope to gain from the bet, they place the bet also to demonstrate their certainty about the issue. Some means of determining the issue at stake must exist. Sometimes the amount bet remains nominal, demonstrating the outcome as one of principle rather than of financial importance.

Betting exchanges allow consumers to both back and lay at odds of their choice. Similar in some ways to a stock exchange, a better may want to back a horse (hoping it will win) or lay a horse (hoping it will lose, effectively acting as bookmaker)