contract. All the contract is about is how much they have to pay the actor. There is a minimum guarantee of being paid for airdays for the period of the contract. Whether or not they actually use the actor isn't a consideration. If they don't use the actor, they still have to pay that minimum.
Actually firing an actor allows them to seek other work I would expect. Plus they may come to a settlement about what's left on their contract. They do have the option of just not using the actor and paying them until their contract runs out.
