The Protean Protagonist is the Player's character. Certain aspects of their history and personality are canon, as a requirement to make the plot work. Others are mutable according to the player's wishes.

History

The Protean Protagonist is an agent of The Hitchhiker's Guild. Their original mission is limited in scope, and they originally intend to leave the ship pretty early. Then they get wind of The Plot and invest fully in the ship and its crew to achieve that mission. 

Branches

Hitchhikers are generally good people, but as their network grows they do run the risk of abuse of power. There are a few opportunities to abuse this power along the way.

Description

Appearance

Customizeable race and appearance would be nice, but are obviously a stretch goal since the investment vs. reward is high.

Personality

Option A: Protean. Offers the most player choice, but also tends to make the protagonist sort of a non-person void. So the realness of the character depends on the player's willingness to invest their own roleplaying into it. But this is a common convention of mainstream RPGs and I don't hear many people complain about it, so maybe it's just me.

Option B: Canonical. Less player choice, but makes the protagonist more of a solid character, with more well-defined relationships with NPCs. Still allows for some player choice, just to a lesser degree.

Abilities

Abilities should be fully open to player choice.