Game Development Reference
Geocaching and Reverse Geocaching
Geocaching is the oldest form of gaming involving GPS. It originated after selective
availability was removed from GPS, making it more accurate, in the year 2000. In its
most basic form, it is the process of hunting down a “cache” using provided GPS coor‐
dinates. The cache usually has a logbook and may contain other items such as coins
with serial numbers that the finder can move to another cache and track online.
Because of the large amount of setup involved in implementing a geocaching game on
a commercial scale, most implementations are community based. However, reverse ge‐
ocaching has more promise for the gaming industry. In this variation there is nothing
at the supplied coordinates, but traveling to them is required to execute some action.
Think of it as carrying around a cache that cannot be unlocked until it is within range
of some specific coordinate. This could be used to force users to travel in order to unlock
a game item. For instance, perhaps to gain the ability to use a sword in a game, the user
must travel to the nearest sporting goods store. The commercial possibility of corporate
tie-ins is an obvious plus.
Mixed-reality games are similar to geocaching. They go beyond just using the coordi‐
nates of the user to trigger events, to using reality-based locals. A current example is
Gbanga's Famiglia . In this game your movement in the real world allows you to discover
virtual establishments in the game world. This divorces it from the actual physical lo‐
cations that your GPS is reporting but requires moving between locations in the real
world to move your character in the virtual world. Popular right now is the FourSquare
app on mobile devices. This is the simplest possible implementation of mixed-reality
gaming. FourSquare allows a user to become the mayor of a place if she “checks in” at
the locale more than anyone else.
Street games are another step beyond mixed reality. These turn the environment around
the user into a virtual game board. One example is the recent Pac-Manhattan multi‐
player game using GPS in smartphones to play a live version of Pac-Man in Washington
Square Park. In general, the idea is to create a court for game play using the environment
surrounding the user. The relationship between users is tracked in the virtual space of
the game and provides the interactive elements.