If you are obliged to do something, a situation, rule, or law makes it necessary for you to do that thing.

To oblige someone means to be helpful to them by doing what they have asked you to do.

People sometimes use obliged in expressions such as 'much obliged' or 'I am obliged to you' when they want to indicate that they are very grateful for something.

If you tell someone that you would be obliged or should be obliged if they would do something, you are telling them in a polite but firm way that you want them to do it.