In order to fill seats at a poker table, some casinos/card rooms allow their staff members (including managers) to sit in on a game. This is an example of a “prop” player. It’s short for proposition and their function is to get games started and/or keep them going when a table is short-handed. Most often, when the table fills up, they leave. The employee plays with their own money while being paid an hourly wage. Recently, a poker room manager told me he only plays to break even, so there are no hard feelings from the clientele. So when your last dealer turns up next to you taking an open seat, you know he’s a prop player.