When a Pokemon is nearby, you can use your phone's touch screen to try to catch the creature in a Poke Ball.
Poke Balls and other items can be found at "PokeStops." These are located in the real world at places like "public art installations, historical markers, and monuments," though a list of specific destinations was not provided.
Pokemon Go will also invite players to join a team and take part in Gym Battles. As with PokeStops, Gyms are also found at real places in the world.
In terms of battle mechanics, here is how The Pokemon Company explained the setup:
"Players can battle using the Pokemon they've caught to gain control of a Gym. By using their own Pokemon's attacks and dodging incoming attacks by swiping left and right on the screen, Pokemon Go players can defeat the defending Pokemon to reduce the Gym's Prestige," reads a line from the game's description.
"Once the Gym's Prestige reaches zero, the defending team loses control of the Gym, and the victor's Pokemon can be assigned to defend the Gym. When a team has control of a Gym, team members can increase its Prestige and level by training their Pokemon with other defending Pokemon. As the Gym gets to a higher level, the defending team gains the ability to assign more Pokemon to defend it. They can also team up with friends and battle together at a rival Gym to take down stronger Gyms faster."
Set to launch in full this year for iOS and Android devices, Pokemon Go is a free game, but players can spend real money to buy PokeCoins, the in-game currency. These can be spent on power ups and other items.
Pokemon Go builds off Niantic's work on the similar, location-based real-world/video game hybrid Ingress. It's part of what Niantic is calling its "Real World" gaming platform, which aims to motivate players to go outdoors and explore the real world.