From Bulbapedia, the community-driven Pokémon encyclopedia.
A Gym (Japanese: ジム Gym) is a type of location in Pokémon GO.
In the Map View, Gyms are marked as color-coded towers with the Gym symbol above them. If the Gym belongs to a team, the top of the tower will swap between the Gym symbol and the Gym's newest added Pokémon.
A Gym claimed by Team Valor, with a Metagross
as its newest addition
Gyms are fixed locations in the real world that players must physically visit to battle. Gyms are generally in public locations, including (but not limited to) public artwork/murals, libraries, famous landmarks, churches, police stations, fire stations, and public parks. While players must be physically close to Gyms to battle them, they generally do not need to enter the building to be close enough (if the Gym is a building).
Gyms are based on a selection of portals from the Niantic game Ingress. Until 2015, Ingress players could submit proposals for portals which subsequently had to be approved by Niantic. Gyms are less common than PokéStops, which were also created from Ingress portals. This distribution was slightly balanced, after some PokéStops were converted into Gyms on June 19, 2017.
If for some reason a physical location is unsuitable as a Gym, players may send a request to Niantic via the Pokémon GO website or Niantic Support official Twitter account to remove it from the game. This could be due to safety concerns or if there is an error related to the Gym (the landmark no longer exists, never existed in the first place, or has been converted to a different use such as a private residence). It should be noted that this is considered more than a simple movement of the stop with the old one removed from the game and the new position being considered a new PokéStop. As a result, any active Exclusive Raid invitations are revoked.
Inspecting a Gym
If a Gym tower is visible in the Map View, it can still be inspected even if it is outside of range.
If the player is not on a team and below level 5, they will be advised to return at level 5. Once they are at least level 5, they will be given the option to select a team. Once the player selects a team, it cannot be changed without submitting a request to Niantic.
If the player is on a team, they can view the Gym screen, which shows the location's name and photo in the top-left corner and any Pokémon defending it. When a defending Pokémon is selected, the following information will be displayed:
- Pokémon name (or nickname if owned by the player)
- Hologram of Trainer's avatar with name and Trainer level
- Total time defending
- Number of Berries (treats) fed to
- Number of battles when defending
If the Gym is of the player's team, they may feed Berries to defending Pokémon to increase their Motivation and CP, and if there are less than six Pokémon already defending it, they may deploy a Pokémon at full health to defend the Gym.
Searching a Gym
Like PokéStops, a player can search a Gym by spinning its Photo Disc to collect items and/or Eggs and gain experience; the Photo Disc can be accessed by tapping the Photo Disc icon in the bottom right corner, then spinning the Gym's Photo Disc while within range. Once the player has spun a Gym's Photo Disc, it will turn purple for that player only for five minutes; the player cannot search a purple Photo Disc until it returns to the Gym's color again.
The pool of items that can be found by searching a PokéStop or Gym increases with the player's Trainer level, with certain items not being obtainable until later levels. The player will not find Eggs at PokéStops or Gyms if they already have the maximum nine Eggs. Multiple of the same item can be obtained from a single search. If a player does not already have a Gym's Badge, spinning its Photo Disc will award them the Gym Badge.
Players always receive two or three random items from a Gym's Photo Disc, but can receive additional items from various bonuses. If the Gym is under the player's team's control, they will receive one additional item. Depending on the level of the player's Gym Badge, they can receive up to three additional items. If the player achieves their First PokéStop of the day bonus using a Gym, they will receive those bonus items.
Once per day, the player can obtain a standard Raid Pass from a Gym. If the player opens the Gym screen of a Gym they are in range of that has an active Raid Battle that they have not already completed, the player will receive a standard Raid Pass automatically if they do not currently have one and have not already received one that day. If the player spins the Photo Disc at a Gym while they do not have a standard Raid Pass and have not already received one that day, they will always receive a Raid Pass in addition to the other items found; even if the player's Bag is full, they can still search a Gym if it would award them a Raid Pass.
The first time a player visits a Gym and spins its Photo Disc, they will receive a Gym Badge for that Gym. All subsequent actions taken at that Gym—stationing a defending Pokémon, participating in a Raid Battle, spinning the Photo Disc, or battling a Pokémon—will reward the player Badge Experience to level up the Gym Badge through Bronze, Silver, and Gold levels. Each additional level of the Gym Badge rewards the player an additional item when using the PokéStop at that Gym and an additional 25 Trainer XP (before team bonuses are factored in). Items obtained as a Badge bonus are shown in a yellow bubble.
|| Min. Badge XP
|| Trainer XP
|| 0 XP
|| 25 XP
|| 31 XP
|| 500 XP
|| 50 XP
|| 63 XP
|| 4,000 XP
|| 75 XP
|| 94 XP
|| 30,000 XP
|| 100 XP
|| 125 XP
Earning Badge experience
Players can earn Badge experience the following ways:
|| Badge XP
| Completing a raid
|| 1,000 XP
| Defeat a Pokémon defending the Gym
|| Defender's CP / 100
| Deploy a Pokémon to defend the Gym
|| 100 XP
| Feeding a Berry
|| 10 XP
| Defend a Gym
|| 1 XP per minute
Gyms are colored based on which team has Pokémon deployed to defend it. Controlled Gyms may be blue for Team Mystic, yellow for Team Instinct, or red for Team Valor. A controlled Gym will have the most recently-deployed defending Pokémon on top of the tower marking the Gym. If a Gym tower is white, that Gym is currently not controlled by any team, meaning that a player from any team can claim it.
A Gym can house up to six defenders. If a player is in range of a Gym that is controlled by their team (or is not controlled by any team) and has fewer than six defenders, they can place one of their Pokémon that has full HP as a defender in the Gym; if the Gym is controlled and has been attacked in the last ten minutes, the player cannot place a Pokémon in the Gym due to it being under attack. The player's current Buddy Pokémon cannot be placed in a Gym. While in a Gym, Pokémon cannot be evolved, Powered Up, traded, or used for battle at another Gym. Legendary Pokémon and Mythical Pokémon, except Meltan and Melmetal, cannot be placed to defend Gyms, but they can still be used to attack opposing Gyms and in Raid Battles.
If a player is in range of a Gym that is controlled by an opposing team, they can challenge it to lower the opposing Pokémon's motivation and attempt to remove them from the Gym. When a Pokémon loses a battle, its motivation decreases; while in a Gym, a Pokémon below maximum motivation has its CP decreased proportionally while it is in the Gym. (The Pokémon's CP is only decreased while it is in the Gym, and returns to normal once it returns to its Trainer.) When a Pokémon's motivation is 0 after being defeated, it leaves the Gym and returns to its Trainer, giving a PokéCoin defender bonus based on how long it was in the Gym.
If a player wins a Raid Battle at a Gym under their team's control, they will also receive two bonus Premier Balls.
Every defender Pokémon has a level of motivation represented by a heart-shaped meter. A defender at 100% motivation will have 100% of its total CP, while a defender at 0% motivation will have 20% CP. A Pokémon initially deployed to defend a Gym will start at 90% motivation (about 92% of its CP). If a defender's motivation falls to 20% or under (about 36% CP), its motivation value will be displayed in red, and its Trainer will be notified that their Pokémon needs a Berry treat. If a defender's motivation is at 0% after losing a battle, it will be knocked out of the Gym and return to its Trainer.
A defender's percentage of CP in relation to motivation is:
%CP = 20% + 0.8 * %Motivation
A defender may lose motivation in several ways:
- Motivation passively decays at a rate that scales with the defender's maximum CP
- If defeated, the defender will lose about 35% motivation (or 28% CP)
- If victorious (by knockout, forfeit, or timer expiring), the defender will still lose 2% motivation (or 1.6% CP)
Even when not battled, a Pokémon defending a Gym will experience gradual motivation loss over time. Motivation decays at a constant rate that is based directly off the Pokémon's maximum CP, and it is updated every 15 seconds. The following table shows how long it would take for a Pokémon at 100% motivation to passively decay to 0% at each CP. 
|| Total hours
| 301 - 2323
|| 250.35 - 72 × log10(CP)
The following table shows the calculated motivation and CP decay for every hundred CP values. Decay for CP values between listed entries can be approximated by taking a weighted average of the upper and lower bounds.
|| Total hours
|| Hourly motivation decay
|| Equivalent CP decay
If a player is in range of a Gym that is controlled by their team, or has a Pokémon defending the Gym and views the Gym remotely, they can restore the motivation of Pokémon in the Gym by feeding them Berry treats; more motivation is restored if the player is in range. Each time a Berry treat is fed, the player earns 20 and 10 XP towards their Gym Badge. Occasionally, feeding a Berry may also yield a Candy of the fed Pokémon.
A player can only feed up to ten Berries to the same defender, and up to ten different defenders, within a 30-minute interval. And within a 30-minute interval, Berries fed from the same player to the same Pokémon have a diminishing effect on its motivation. If a player has a Pokémon defending a Gym, they may remotely feed Berries to any Pokémon at that Gym, but only at 25% effectiveness. Golden Razz Berries, regardless of distance, will always restore a Pokémon to full motivation.
Increase in % Motivation (% CP) 
| # Berries
Silver Pinap Berry
Golden Razz Berry
|| 15% (12%)
|| 18.75% (15%)
|| 30% (24%)
|| 6% (4.8%)
|| 7.5% (6%)
|| 12% (9.6%)
|| 3% (2.4%)
|| 3.75% (3%)
|| 6% (4.8%)
|| 1.5% (1.2%)
|| 1.875% (1.5%)
|| 3% (2.4%)
|| 1.2% (0.96%)
|| 1.5% (1.2%)
|| 2.4% (1.92%)
|| 1% (0.8%)
|| 1.25% (1%)
|| 2% (1.6%)
|| 31.7% (25.36%)
|| 39.625% (31.7%)
|| 63.4% (50.72%)
While a raid is active at a Gym, the motivation of Pokémon defending that Gym is frozen; their motivation does not decay over time and players cannot feed Berry treats to them.
When the defending Pokémon returns from Gym to its trainer, it brings a defender bonus in the form of PokéCoins. This is the only way to obtain PokéCoins without buying them with real money.
The player receives 1 per 10 minutes defended, capped at 50 per day (achieved by defending for 8 hours and 20 minutes). Daily limits on defender bonuses are counted towards the day the Pokémon returns from Gym. If a Pokémon was placed in a Gym on Monday and returned the following Tuesday, the PokéCoins earned will count towards Tuesday's daily limit. If the Pokémon were to return on Wednesday, the bonus will count towards Wednesday and will not receive any for Tuesday.
A Pokémon battle at a Gym
In Pokémon GO, battles can be conducted at Gyms between Trainers on opposing teams. Battles are not turn-based, and they are conducted between a player and a computer-controlled opponent and have a time limit of 99 seconds per defender. Defending Pokémon are battled in sequence, from the oldest defender to the newest.
When battling a Gym, the player selects a team of six Pokémon of their own to battle against the defending Pokémon. Each defending Pokémon defeated will award XP to both the player and their associated Gym's badge. Defeating only one defending Pokémon counts as a victory towards earning medals and completing certain Field Research tasks, regardless of how many of the player's Pokémon fainted. Conversely, each time a player's Pokémon is knocked out, it counts as a victory towards the Gym defender.
After defeating a Pokémon, the player has ten seconds to decide whether to battle the next defender or leave. If the player leaves, it won't be considered as a player's defeat. If the player chooses to re-battle again, they will again start by battling the first defender in the lineup.
During a Gym battle, the player's Pokémon will take damage, lowering its HP and potentially causing it to faint. A battle-damaged Pokémon can have its HP and consciousness restored with healing items, such as Revives and Potions.
Players can work together to challenge, with the defending Pokémon's HP being shared between players. An icon with a number will appear underneath the countdown timer of the screen indicating the number of players currently fighting that Gym. Up to 20 trainers can battle together. Challengers who have high friendship levels with each other will deal extra damage per attack.
Battles are shown with the Gym's defender Pokémon at the middle of a circular arena and the attacking Pokémon at the circle's edge. Each time a new defender Pokémon is sent out, the battle timer will reset to 99 seconds.
Each Pokémon has three stats which are relevant to Pokémon battles: HP, Attack, and Defense. A Pokémon's Combat Power (CP) is derived from those three stats. A Pokémon loses HP when it is hit by attacks, and faints when its HP is depleted. Damage dealt by attacks is mostly determined by the user's Attack stat, the target's Defense stat, and the attack's power. Additionally, special type effectiveness rules apply in Pokémon GO; type effectiveness is derived from the type chart in the Generation VI core series games, but there are no immunities and different multipliers. The same-type attack bonus is applied, giving a 20% boost to moves of the same type as the user. In Gym battles only, attacks with a weather-boosted type also gain a 20% boost, which can be seen on a Pokémon's summary page if applied.
- See also: Damage → Pokémon GO
During a battle, the player can forfeit by tapping the button at the top-left of the screen. If the player forfeits, runs out of time, or has no more usable Pokémon left, it counts as a victory for the defending Pokémon. The challenge can immediately rebattle the Gym, in the same order of defending Pokémon.
During battle, the player's Pokémon can perform one of three basic actions:
- Fast Attack: tap the screen.
- Charged Attack: tap the Charged Attack's button when the energy meter is sufficiently charged.
- Dodge: swipe left or right on the screen.
- Dodging an attack within the damage window mitigates damage by 75%. Dodging has a duration of 0.5 seconds.
Challengers may swap out a Pokémon for another in their battling party at any time by tapping the button on the bottom-right of the screen. This action has a one-second duration.
A Pokémon starts off with zero energy when it is sent out (even if it previously battled but was switched out) and gains energy by casting Fast Attacks. For every HP damage taken, the Pokémon also gains 0.5 energy. If the Pokémon stays on the battlefield after defeating an opponent, the Charged Attack meter is retained. The energy meter is displayed at the bottom of the screen below the Charged Attack button.
The amount of energy required by a Charged Attack depends on the number of bar segments for that move (visible on the status screen). Charged Attacks with more bar segments use less energy for a single use, so can be used more frequently than Charged Attacks with fewer bar segments. Typically, Charged Attacks with higher power require more energy per use. Consequently, weaker Charged Attacks can typically be used more frequently than stronger ones. Previously, before the Charged Attack button was added, the Charged Attack appeared in the top right of the screen below a Pokémon's HP and was activated by holding down on the screen.
- See also: List of moves in Pokémon GO
A Pokémon defending a Gym is controlled by the game's AI and behaves more predictably. The differences between an AI-controlled defender and a player-controlled challenger are that a defender
- Has double its standard HP (adjusted for drops in motivation)
- Does not swap out
- Does not dodge attacks
- Pauses for 1.5 seconds between attacks (effectively adding 1.5 seconds to all attack durations)
- Has a 50% chance of casting a Charged Attack, given enough energy
- If a defender knows two Charged Attacks and has enough energy for both, it will randomly cast either one
- Main article: Raid Battle
Raid Battles can also take place at Gyms. A wild Pokémon, typically one much stronger than can be found in the wild, will be stationed at the Gym for a period of time. Using a Raid Pass players can challenge the wild Pokémon and fight it as though it were a Gym defender.
EX Raids are exclusive raids given out by invitation only to players that have raided at a gym at some point in the previous week. They allow the player to battle against Legendary or Mythical Pokémon that may be otherwise difficult to obtain.
Gym System updates
|| This section is incomplete.|
Please feel free to edit this section to add missing information and complete it.
Reason: more information on updates.
There have been many updates introduced to the Gym system since the game's implementation, mostly related to the players quality of life. Various changes include moving the Charged Attack gauge and changing the execution from a long press on the screen to a button, moving around the other elements of the UI, and adding a small battle log to the bottom right delivering players information regarding move effectiveness.
Early Gym system
Inspecting a level 4 Gym controlled by Team Valor (red)
- Main article: Prestige
When the game first released the Gym system was very different. Each Gym was capable of having ten defenders, and there was no limit on the species of Pokémon defending. They were ordered with the lowest CP Pokémon at the bottom, going up in rank to the highest CP. Instead of motivation Pokémon had prestige, and players of the defending team could train at the Gym to increase this value and make it harder for opposing teams to defeat the Pokémon and ergo the Gym. Furthermore, the defender bonus was determined by the amount of Pokémon you had in Gyms, for a collection of a hundred PokéCoins a day.
This caused a lot of stagnation and power imbalances early on in Gyms during the release of the game as weaker players had issues taking down Gyms with especially powerful Pokémon defending them. It was significantly more time consuming and difficult to defeat Gyms as Pokémon never lost CP and only lost Prestige as they were defeated. Players that had positions in ten Gyms had no reason to take down other Gyms rather than maintain their positions in the current Gyms as Gym Badges weren't yet implemented. Additionally, if your Pokémon was at the top of a level ten Gym, a players position was fairly secure as attackers would have to battle their way through the previous nine Pokémon before being able to fight the top position. It created a situation of the strong getting stronger, with the weak being unable to catch up, due to the "free" in-game currency and the bonuses one could buy with it (such as incubators and bag space) and extra Stardust which allowed them to strengthen their Pokémon.
The new system improved on all of this by introducing the motivation mechanic, limiting species within a Gym, lowering the amount of Pokémon defending a Gym, and only rewarding PokéCoins once a Pokémon was returned to its player.