In contract law, the talents of a person which are unusual, special or unique and cannot be performed exactly the same by another. these can include the talents of an artist, an actor, a writer or professional services. the value of personal services is greater than general labor, so woodcarving is personal service and carpentry is not. therefore, if an actor contracts to perform in a movie and fails to show, he/she will be liable for damages based on the difficulty to replace him. an artist who contracts to paint a picture cannot send a substitute, since he/she was retained for his/her unique ability and product.