The Player character is one of the main protagonists of the Pokémon Mystery Dungeon series and has appeared in every game to date. According to the player's decisions in the personality quiz, he or she can get up to 19 different Pokémon results.
Per tradition in most Pokémon games, the player character has very few if any speaking roles in the actual dialogue of the game. However, the Pokémon Mystery Dungeon has a few parts in which the player actual speaks. (Most of the time their dialogue is in their thoughts, implied by them speaking in parenthesis like this.)
The player is usually very intent on doing the right thing. However, they very rarely push their beliefs or ideas onto others and slowly let other characters (usually the partner) come to terms that their idea may be legitimate. The player is also very caring for anyone they consider a friend and usually quite prepared to protect them from anyone they consider an enemy.
Despite this, much of the personality is left up to the player because of the few speaking parts that are shown. it is generally believed that this is because the game leaves it open to the player themselves to decide how they would react to every situation.
Roles in the games
In Red/Blue Rescue Team
Plot and/or ending details may follow.
In Red/Blue Rescue Team, the Player awakes in a grassy field with no memory of anything other than their name. They meet the other Pokémon responsible for waking them up. After a short exchange, a Butterfree approaches.and informs them it's baby has fallen into a crevice and cannot get it out. The Pokémon volunteers you both and you go in to rescue the Butterfree's child.
After you finish that job and receive your reward from the Butterfree, your new partner asks you rather bluntly if you would like to join a rescue team with him or her. As you of course accept, your rescue team begins, as does the game itself.
From there, you and your partner do simple tasks and rescues.