A contract of carriage is the agreement you sign whether you mean to or not every time you confirm your purchase of a flight from anywhere to anywhere. It lays out what you can and cannot do, the things that the airline is required to provide to you, and what happens when things don’t quite go according to plan.
The most important part here is what happens when things don’t quite go according to plan. The trick with this is that your contract of carriage is a mix of legal language and individual airline rules. Suffice it to say that you’ll need to take a peek at the one for your particular airline. You’ll find that they all have some similar themes, but individual intricacies for the benefits they are willing to give in the event things don’t really go to plan.
Delays due to weather are always gonna not be the fault of the airline, cuz ya know an act of god and all. As annoying as it is, delays do happen sometimes. How long do you have to be delayed to get those sweet sweet flight vouchers? That depends on the airline. American requires 4+ hours delay.
Just in case you were interested in something that might send terror down your spine, did you know that a plane can leave before it’s scheduled departure time? If all the passengers are on board why should the plane be forced to wait to take off? It’s not. It can take off even if it is only missing a single person. The entire inconvenience of being required to be at the gate 30+ minutes before departure is there to get us all in one place at one time so that flights can take off.
Read your contract of carriage. It will be boring, but it could net you hundreds of dollars.