How does a Muslim intend to fast Ramadan, and when is the intention obligatory?

The intention for fasting is made by resolving to fast, and it must be renewed every night in Ramadan. However, some scholars hold that the intention made at the beginning of Ramadan is sufficient for the entire month, as long as the continuity is not broken by a valid excuse. If it is broken, then the intention must be renewed. This latter opinion is the most correct and reassuring one.