A location-based game (or location-enabled game) is one in which the game play somehow evolves and progresses via a player's location. Thus, location-based games almost always support some kind of localization technology, for example by using satellite positioning like GPS. "Urban gaming" or "Street Games" are typically multi-player location-based games played out on city streets and built up urban environments.
Current research trends are looking to other embedded mobile technologies such as Near Field Communication, Bluetooth, and UWB. Poor technology performance in urban areas has led some location-based games to incorporate disconnectivity as a gameplay asset.
Some games only last for a certain amount of time, while others can be played any time. Some are location-dependent while others can be played anywhere. Narrative elements have become important elements to enabling locative media to progress gameplay.
Geocaching is the most prominent example with a large community. It is nominally a single-player kind of treasure hunt which is usually played using hand-held GPS receivers with user-hidden boxes.
There are many location based games throughout the world:
Keitai Kunitori Gassen (Battle for the Countries), operated by Mapion Co. in Japan. Players become warriors whose objective is to unite the 600 "countries" that make up the Japanese archipelago. Players take over a "country" when they actually set foot there and input the location information using GPS. It's like a giant "stamp rally" (a real-life game in which players get their cards stamped for visiting particular locations) played out across the whole of Japan.
Also, players accumulate koban, the game's currency, by answering questions about Japanese history. Koban can be used to purchase armor, horses, and other items at virtual shops. There are also real-life events held for players of this virtual game. Some players exchange information about their "countries," and others enjoy dining out and sightseeing in the "countries" that they have taken over. The number of players topped 380,000 in January 2010.
Killer is a world-wide iPhone GPS-based MMORPG where geolocation data is combined with pictures of players and Bluetooth contact is used to confirm close contact between players.
GeoCaching, Combat and Caching are just some of the games that are held under active urban games network Encounter. They have various rules that single them out from similar games. The most noticeable differences are time limitations to every game, team-play is more common and the fact that anyone can be an organizer.
Turf Wars is a GPS-based Mafia game for iPhone and iPod Touch. The game centers around players claiming and defending real-world territory, in order to increase their "influence" over a city.
Parallel Kingdom is the first GPS-based MMORPG for the iPhone and Google Android phones. The game uses the GPS capabilities of these devices to place an avatar on a Google Map at the player's actual location. That is where the player begins his or her game career. The avatar then has roughly a 1/3 mile radius that can be explored by tapping on the screen of the device, so no real movement is necessary. However, to go farther the player needs to use other means available in the game or physically move in the real world and use the "Relocate" function in the game. Parallel Kingdom is available globally, for free, and currently has over 70,000 players.
Traveler's Quest by Kitty Code, LLC is a family oriented GPS-based Treasure Hunt game which uses the iPhone's GPS location services to help you find and bury virtual treasure in the real world. With in-game stores for each city, and the ability to pilfer treasures buried by other players, this game becomes addictive very quickly as you check for new treasures and maps near you. Traveler's Quest is ideal for people on the go, whether running errands locally, or touring the globe with friends, family and colleagues. The in game maps show your location, the treasure location and your distance from the selected treasure. In game leaderboards show top 25 players in over all score, gold, treasure and collections. Traveler's Quest revolves around how far away from the treasure's origin you can bury it, so taking a treasure from Edinburgh, Scotland to London, England, or any large distance will make the treasure worth much more gold when buried, but be careful, another hunter can dig your treasure and have that gold bonus working for them! The game is currently played world wide with players on every continent. The game also has Facebook integration, allowing you to tell your friends when you've pilfered their treasures and the Facebook Fan Page allows you to talk with other players from the game who are as close as your city, and as far away as Russia. Traveler's Quest was a 2009 Best App Ever Double Nominee   Reviews: 
Schnapphans is an entertaining and informative transGo based game taking visitors around the city of Jena/Germany. Produced by Art + Wege and designed and implemented by transformat using their flexible transGo positioning framework  this game was developed in just 3 Months from the point the story bord was finished.
FastFoot-Challenge is a GPS game released by urban team. Like a real world version of the well known board game Scotland Yard, 3 or 4 "Runners" try to catch an "X" in a defined playing field and time, typically a circle of 1 km radius within 30 min. Like in the board game, any means of public transportation may be used. After a closed beta testing phase from August 2007 until May 2008, the 1.0 stable version was released in June 2008.
LocoMatrix is a gaming platform based on mobile phones and GPS (either incorporated on the phone or as a linked Bluetooth module). There are a couple of example games available - Fruit Farmer and Treasure Hunt - both of which can be modified at the LocoMatrix website. Further games are being developed as is a programming interface which will allow external developers to create their own games. One of the aims of LocoMatrix is to try to encourage younger people to play outside.
Tourality is a real life multiplayer GPS game for mobile phones that support Java ME and GPS (integrated in the mobile phone or as an external Bluetooth GPS receiver). The challenge is to reach geographically defined spots by running, biking or driving before others in realtime. So called 'Spots', 'Points of Interest' and 'Game-Templates' can be created with Google Maps by users in supported areas on the website. This user-generated content is the basis for outdoor games. Tourality offers a singleplayer and two multiplayer (player vs. player and team vs. team) modes. Currently the game is available as a free beta version.
Torpedo Bay uses the area in and around you to avoid being killed by various ocean warships (carriers etc.) To survive, you must move in your neighborhood to get more ammunition and health to stay alive. GPS enabled mobile handsets allow for real time location information. This game is available on Boost Mobile and Nextel in the USA since 2005 and also published by Blister Entertainment.
Sidewalk Squirrel is a single player location based game that allows anyone to create a gameboard in any neighborhood. Gameboards consist of a map, acorns, bones, a start and finish flag and are created on http://www.SidewalkSquirrel.com or using the Sidewalk Squirrel game. To play, individuals become a squirrel within a gameboard using GPS, Windows Mobile and the Sidewalk Squirrel game. The object of the game is to run the gameboard course picking up acorns and bones for points while avoiding attacking dogs (life as a squirrel). Dogs are also satisfied when given collected bones. Sidewalk Squirrel is Sneaker Entertainment's debut game.
The Journey (part 1 + 2) are mobile, location based adventure games developed by Mopius, which run on standard Symbian OS-phones. They combine the virtual world of a detective with the real surroundings of the player, while he is playing the game. The game is based on cell IDs of the mobile network, which has the advantage that no additional hardware like GPS receivers is required and that playing the game is free (no data traffic or location acquisition costs). As the virtual world is built dynamically during each game, The Journey can be played anywhere on the world and does not need prior setup. The first game was released as an open source game through the GPL-license. Both games have already been downloaded more than 100.000 times since their release in 2004 (state: 2007).
Catch&Run is a game when players have to catch each other in real world. Players can see each other on the map and when they get close enough, the chase starts. One becomes 'catcher' and the other 'runner'. They are rewarded for their performance by virtual money. Game is in early stage of development and currently seeking for testers and enthusiasts in this Google Group.
Uncle Roy All Around You and Can You See Me Now?, produced by Brighton based Blast Theory and the Mixed Reality Lab at Nottingham University, are examples for of mixed reality and locative media breaking the arts/science/computer games barrier. Their games implement GPS via PDAs.
Wherigo (Where I Go) is "an adventure game construction set for the real world" currently available for Garmin Colorado and GPS-enabled Pocket PCs. It uses user-developed content (called a "cartridge") which is mostly location-dependent, but cartridges can be built to be played anywhere. The Wherigo web site is maintained by Groundspeak, the same company that maintains geocaching.com.
Game publisher La mosca has developed until now 6 location-based games to be used immediately in any urban surroundings, and several other games specifically for a certain area or territory. Currently the games are played in Belgium, the Netherlands, France, Spain and Italy. Players can rent GPS phones to play the games. The target is a real life pursuit game, Treasure of the Monk is a technological Treasure Hunt, City Explorer and City Tracks helps people discover a new city with touristic information, Code Crackers is the modern version of Robin Hood and The Managers is a real business game.
GPS Mission is a gaming platform requiring GPS-enabled mobile phones as well as an online connection during play. GPS Mission involves collecting virtual goods in the real world. Games can be created using a web-based tool.
Cipher Cities is a web-based authoring tool and social network for building, sharing and playing location-based games. Members can play games on mobile phones using their web browser  or SMS. There is also a simple web based builder that allows members to create games.
BotFighters, developed by It's Alive! and released in 2000, was one of the first location-based games on mobile phones.
Swordfish uses the area in and around you to go fishing for virtual swordfish. GPS enabled mobile handsets allow for real time location information where the swordfish are in your neighborhood. This game has been available since 2004 on Bell Mobility Canada and is available on Boost Mobile and Nextel in the USA. Swordfish won the Excellence in Gaming category at the 2005 Canadian New Media Association Awards. Written in Java ME, the game is published by Calgary, Canada based Blister Entertainment (a wholly-owned company of KnowledgeWhere Inc.) 
outWord is a location-based word game for the iPhone/iPod Touch. The objective of the game is to build words out of virtual letters that are scattered throughout the world. To use the letters, you must be physically near them. It is similar to Scrabble in that longer words are worth more points.
Poligonia is a battle among virtual polygons drawn on a real territory. Each polygon moves to capture antagonist’s vertexes within its own surface. The polygons represent teams consisting of at least one player; they are identified with vertexes that, at the beginning of the game, are virtually placed on the battle field by the team leaders and then are moved by the players that move physically in the territory. Players use a smartphone with a GPS receiver and an Internet connection to communicate their position and to check the status of the battle.
Some of the Garmin GPS receivers (including the Geko 201, Geko 301, GPS 60, eTrex Vista C, and GPSMAP 76CS) include the geolocation games Geko Smak, Memory Race, Virtual Maze and Nibbons.
In 2006, Penn State students founded the Urban Gaming Club. The goal of the club is to provide location based games and Alternate Reality Games. Some of the games played by Penn State's UGC are Humans vs. Zombies, Manhunt, and Capture the Flag.