Finding the right cast is a key task in pre-production.

The director, with the help of a casting director and in close consultation with the producer, is responsible for the selection of actors. They begin the casting process according to the importance of the roles: they start with the most important or the most difficult to fill role, usually the lead role, and work towards small daily roles. By doing so, they ensure that they have the widest possible scope for the important role, and that they can cast the actors in relation to each other. This creates a coherent overall picture. In contrast to extras, all actors and bit-part actors are cast. Mute roles are cast only when the performance requires acting talent.

The decision-making criteria for the cast are diverse: in addition to finding the right type of actor with the required talent, factors such as creativity, mutability and mutual sympathy, the ability to translate the director's language into the desired result and a common vision, are all part of the skills required for a role. The chemistry between the actors is also an important factor and, if necessary, special abilities may be required. From a production point of view, the actor's wage demands are also a factor, as well as his or her temporal availability, insurance costs and marketing potential.

The casting director draws up staffing proposals on the basis of content and production specifications and queries the agencies of the relevant actors about the availability of their clients. Since all the scenes of a film are rarely shot in one piece, temporal restrictions have a negative impact on the flexibility of the shooting process, which is why casts with limited availability are avoided. Days when an actor is not available are called off-days. They are an integral part of the contract and the production must blindingly adhere to them.