Much like Pokéstops, Gyms are actual landmarks out in the world, and they are where real Pokémon battles happen. You can claim them for your team, or help level up a Gym already claimed for your team to gain build up its prestige. Trainers can take over an unoccupied Gym and claim it for the Red, Blue, or Yellow team. If your team's color is in control of a Gym, you are able to train in it. If a Gym is already held by an opposing team, you'll need to battle the Pokémon holding it to lower its prestige. This triggers a fun mini-game where you'll need to attack the opposing Pokémon, and dodge their attacks. When battling, you have three options. You can tap the screen to attack, press and hold the screen to initiate a special attack, and swipe left or right to dodge an opponent's attack. Just like in traditional Pokémon games, the goal is to reduce your opponent's Pokémon's hit points to zero. Gyms earn prestige when either you train your Pokémon in one that your team controls, and lose prestige when opposing teams win battles against the Pokémon left there. Your team's Gym will earn experience points to gain prestige, which will amount to leveling up the Gym. As its levels increase, so do the number of Gym Leaders. For example, if your Gym has reached level three, you can have three Gym Leaders in it, which makes it harder for opposing teams to overthrow. To steal control of a Gym that is already occupied by an opposing team, you must win your battle against all of the Gym Leaders' Pokemon in it. Beating all the leaders in the Gym will lower the prestige but it will take multiple battles against the same Pokémon in order to occupy it for your team.