Uncredited extra with no dialogue, populating a scene — background presence only. Day-rate hire, union rules don't apply.
On set, the walk-on is the foot soldier of any populated scene — the one who fills the street, sits in the background at a restaurant, or shuffles past as a passenger on a bus. Unlike a speaking extra (who has at least one line), the walk-on contributes nothing that lands on the film's audio track. This makes them more cost-effective to bill, but no less important for the visual credibility of a scene. On set, you work with walk-ons through a walk-on agency — they mediate, coordinate, and handle billing. Payment is based on a daily rate (often 50–150 Euros per day, depending on production size and federal state), not according to collective bargaining agreements like actors with roles.
Practically, this means for production: You need 20 people at the train station? The agency will provide them. Your 1st AD and the walk-on coordinator will brief them in groups, show them the looks — go there, ignore that person, stand behind this pillar. Continuity is critical here: The same walk-on must be in the same position for multiple takes, otherwise editing and background will fall apart. That's why you memorize positions or take Polaroids — or (more modernly) quick video snippets with your phone from the camera's perspective.
A common mistake: using walk-ons too dynamically. They shouldn't act like actors, but like people who don't know they are being filmed. The fleeting, the undirected makes them credible — if they seem too "performative," they magically draw the viewer's eye. This becomes a problem especially with tight shots (close-ups or medium shots): A walk-on in the background who steps too far forward or gestures torpedoes your focus planes.
In post-production, walk-ons have less weight than on set, but a misplaced dozen in the background can necessitate digital cleanup — expensive and time-consuming. Therefore: Think ahead during planning. Book enough (a group of 20 never looks too full), but don't overdo it. And give the 1st AD a clear briefing: who stands where, who moves, who freezes.