Based on my Grandson's enthusiasm (he has been visiting) and a game that encourages walking, I downloaded and started capturing pokemons. The game is free to play, but up front I'll say it is pay to win. You venture out in the real world to find Pokemons most numerous at Poke-stops. The game synchronizes with map providers to designate real world locations as highly probably areas to find pokemons. You start out with 50 balls used to capture these little creatures. At first all seems well with the world of Pokemon, as long as you don't wreck your car trying to capture them , until you run short on balls. They can be refreshed by visiting a poke-stop and spinning the icon, but it can take 1-7 balls to capture them, so this becomes an issue without spending $.* $1 buys 20 balls, that is unless you have the patience to go collect balls. While items can be earned in game slowly, $ buys you balls, incense (to attract Pokemons), eggs, and revive crystals (when your Pokemons get knocked out in the gym), etc. The gym is where the action is having your Pokemon battle other players to take over a specific gym, physical location, so you can only interact with gyms near your physical location, which means you might have to walk or even hop into your car. Gym ownership grants in-game advantages including coins. I thought I was doing well when I evolved my top Pokemon to L256 until I spotted a gym owned by a L926! Oh well, I'll see how this goes. We are visiting relatives and there is a gym right by my house. When I get home, I'll see what is what and report back. *Update- plenty of balls are available through local Poke Stops. If you are actively visiting Poke Stops, you get what you need to play the game.