Four of Kanto's Gym Leaders award badges that boost your active Pokémon's stats in battle.
Badge Effects
| Badge | Stat Boost | Traded Pokémon Obedience | Move Outside Battle |
|---|---|---|---|
| Boulder Badge Brock | Attack +12.5% | No change | Flash |
| Cascade Badge Misty | None | Through level 30 | Cut |
| Thunder Badge Lt. Surge | Defense +12.5% | No change | Fly |
| Rainbow Badge Erika | None | Through level 50 | Strength |
| Soul Badge Koga | Speed +12.5% | No change | Surf |
| Marsh Badge Sabrina | None | Through level 70 | None |
| Volcano Badge Blaine | Special +12.5% | No change | None |
| Earth Badge Giovanni | None | Through level 100 | None |
Stat Bonuses
A badge's stat bonus is 12.5%, rounded down, with a maximum stat value of 999. It applies to your active Pokémon in ordinary battles, including wild encounters, but not in link battles. These bonuses do not change the stats shown on the party screen.
Traded Pokémon Obedience
Without an obedience badge, traded Pokémon obey through level 10. The Cascade Badge, Rainbow Badge, and Marsh Badge raise that limit to 30, 50, and 70. The Earth Badge covers all normal levels through 100.
Pokémon with your Trainer ID obey regardless of level, and obedience checks do not apply in link battles. Above the limit, a traded Pokémon has a chance to disobey every turn.
Field Moves
The field move permissions require a Pokémon that knows the move. A badge does not give you the HM or teach the move.
Pokémon League Entry
All eight badges are also required to pass the Pokémon League's badge checkpoints.
Badge Bugs and Battle Interactions
Thunder Badge and Soul Badge Effects Are Swapped
Lt. Surge says the Thunder Badge increases Speed. Koga says the Soul Badge increases Defense. The battle code does the opposite. Thunder Badge raises Defense, and Soul Badge raises Speed.
The Badge Boost Glitch
When your Pokémon successfully raises a stat, or an opponent successfully lowers one of your Pokémon's stats, the game applies all your badge bonuses again. This includes changes to accuracy or evasion, even though neither has its own badge bonus. X Attack, X Defend, X Speed, and X Special use the same routine and can trigger it too. Failed stat changes do not trigger it.
If Attack, Defense, Speed, or Special changes, the game first recalculates that stat from its original value and current stat stage. That stat then receives one badge bonus. The other boosted stats keep their existing values and gain another 12.5%, rounded down. Repeated stat changes can build up those other stats without increasing their stat stages.
For example, a Pokémon with 80 Attack enters battle with 90 Attack if you own the Boulder Badge. If it uses Defense Curl, its Attack rises to 101. A second successful Defense Curl raises Attack to 113. These extra Attack boosts happen while its Attack stage stays unchanged.
The extra bonuses disappear when you switch the Pokémon out. Its usual single badge bonuses apply when it returns. Badge bonuses and this glitch do not operate in link battles.
Leveling up during battle also recalculates the Pokémon's stats and restores one normal badge bonus, clearing the accumulated extra boosts.
Burn and Paralysis Interact with Stat Changes
A burned Pokémon that raises its own Attack can lose the burn's Attack penalty. A paralyzed Pokémon that raises its own Speed can lose paralysis's Speed penalty. The status itself remains, including paralysis's chance to prevent a move.
That same mistake can repeatedly halve a burned opponent's Attack or quarter a paralyzed opponent's Speed. Stat decreases can also reapply these penalties even when another stat changes.
Haze
Haze copies both Pokémon's unmodified stats back into their battle stats. This clears accumulated badge boosts and the ordinary single badge bonus. A later stat change can apply badge bonuses again, and switching out and returning restores the normal bonuses.
Critical Hits
Critical hits use unmodified Attack or Special for the attacker and unmodified Defense or Special for the target. These hits bypass the relevant badge bonuses, including accumulated boosts. A Speed badge boost also does not raise critical-hit probability, which uses the species' base Speed.