According to the official Academy Award rules, the criteria are: (a) consideration of the contribution the visual effects make to the overall production and (b) the artistry, skill and fidelity with which the visual illusions are achieved.
Segundo as regras da Academia, os criterios son: (a) consideración da contribución que os efectos visuais realizan á produción en xeral e (b) a destreza, talento e fidelidade que logran as ilusións visuais.