How to stop marriage after engagement?

The couple decides and then announces it to both sets of parents and both families.

Where is this, in some cultures the engagement is a legal contract and the party wishing to end it has to compensate the other?

Is this an arranged marriage, issue ?

Was, as is done in some culture, money or property given at engagement?

In some culture, they are considered really married at the engagement announcement?

So where you are, how marriage works in your culture all makes a difference