Name Rater/Re-nameable Pokémon

If the player is the Original Trainer, the Name Rater will say that its nickname could be better and offer the player the option of changing it.

If the Pokémon he is judging is an outsider Pokémon (if it was originally obtained in a different game, via an, or via an in-game trade), he will say that the nickname is perfect and refuse to change it. The Name Rater in Orre will also refuse to rename a Shadow Pokémon until it has been purified.

The method by which the game validates whether the player is a Pokémon's Original Trainer varies between generations:
 * In Generations and, a Pokémon can only be renamed if its Original Trainer name and Trainer ID number match the player's.
 * In Generation III, a Pokémon can only be renamed if its Original Trainer name, Trainer ID number, and secret ID match the player's.
 * In Generation IV, only the player's Trainer ID number needs to match in order to rename a Pokémon.
 * From Generation V onward, a Pokémon can only be renamed if its Original Trainer name, Original Trainer gender, Trainer ID number, and secret ID match the player's.

In Generation I, if the player presses End with no characters in the nickname space, the process will proceed as if the player canceled the nicknaming process, giving the Pokémon its species name. In later games, this is treated as giving the Pokémon the same nickname as before.

In Generations and, tapping the Pokémon's sprite on the nickname screen replaces the currently entered text with the Pokémon's species name. In Generation VI, this replaces the currently entered text with the Pokémon's current nickname.

In Pokémon: Let's Go, Pikachu! and Let's Go, Eevee!, since the player can freely nickname their Pokémon at any time, the Name Rater has been rendered a normal NPC.