Puzzles have always been a central part of games. One of the simplest manifestations of a puzzle in games is an obstruction that prevents the player from progressing and an object that removes the obstruction. The system of unlocking new areas with keys is used in order to provide interesting level design and help build narrative in games. This examination intends to provide knowledge and insight into how this type of system is commonly portrayed visually and thus provide a basis for designers to build upon when creating similar challenges, providing a greater awareness of the design norms that are commonly applied. In the majority of the cases that have been examined during this study, text-based information is used to convey the majority of the essential information given to the players regarding the relationship of the key and the lock. In many cases the graphics serve only to highlight important features of the objects and help the player to quickly tell the different items apart in the inventory.