Character creation (also: character generation or character design) is the process of making a character whose role the Player will assume. Character creation is about realizing the concept of the character within the options and rules of the RPG system.
I am playing a Forgotten Realms game with very specific rules:
1) "All gods in this plane are dead", so there is only one cleric in the game (he is NPC)
2) Only some books are allowed (CAd, Car, CD, ...