Picklock invites the gamer to transform into a thief nicknamed “Masterkey”, who will have to rob all the residents of the city. In this case, you need to act carefully and secretly in order to safely pass by the guards and not fall into the viewing radius of the surveillance camera. The hero will visit different types of stores, climb into houses, penetrate office buildings, nightclubs and even cinemas. The character does not own special devices like bombs and grappling hooks. More often than not, there will be someone else present on the premises: customers, employees or residents.

Before the outing, you need to come up with a detailed plan and foresee events that could interfere. As you progress through the levels, Picklok's difficulty increases. For example, initially there will be no alarm in the NPC’s apartments and they will ignore recordings from video cameras, but gradually the heroes will begin to inspect the location more carefully. Moreover, if the user does not find all the specified things, he will fail the task and the new stage will remain inaccessible.

If a gamer is spotted, he can hide behind the nearest corner or close the safe door. In this case, the panic will quickly subside. The disadvantages of the title include the linearity of the levels and the monotony of enemy actions. The hero must sell the stolen items to the appropriate person. When the protagonist has enough money, he will be able to buy a car, new clothes, an apartment or a country house. The main objective of the gameplay is to purchase real estate.