| Type | Power | Accuracy | PP |
| Water | 95 | 85 | 10 |
| Target | Contact | TM/HM | |
| Both foes | No | -- | |
After dealing damage, Muddy Water has a 30% chance of lowering the targetted pokemon's Accuracy by 1 step on the standard Accuracy scale.
Also, like all damaging moves that strike both opposing pokemon in a Double Battle, each individual pokemon takes 1/2 the damage they would if Muddy Water was used during a normal battle. This makes the attack's power effectively 47 during a Double Battle.
Muddy Water receives the flinching bonus when King's Rock is attached to the using pokémon.
Muddy Water is affected by Brightpowder when the opposing pokémon is equipped with it.