The term farmer is used to refer to a person or action performed in video games, commonly in an MMORPG (massively-multiplayer online role-playing game). A farmer is a player who kills creatures repetitively in a game to obtain valuable materials used for crafting or rare items, such as armor or weapons. When a player is specifically working to gather these materials, they are farming the materials, much like a farmer would work his fields to gather crops.
While not usually a legal action to undertake, some players employ the use of a botting program to farm. Players can often sell their farmed materials to other players, earning game currency in return. Game currencies have a large virtual and real demand and can be sold for real-life money. When traded for real-life money, this action is often called RMT (real money trade).