It has also been my opinion that silent protagonists are a excuse to not create a character for the player. As an avid RPG player, I am all about making backstories to characters I create or making their attributes accurate with a particular race (i.e. my orcs are longsword masters while my high elves are stingy-looking mages). When action-adventure games give no dialogue for the protagonist, I feel the reverse of identifying with the character. If the character doesn't talk, how do I know if how he feels about his situation. I don't want my avatar to be bossed around and pushed into situations that he isn't comfortable with. But if the protagonist neve speaks, I just have to assume the complications of his character.
With this new discussion, I did a little research. Here are some definitions to start:
Silent protagonist: a character in a game who speaks no lines of dialogue, letting other characters tell the story in scripted moments or cutscenes. "Let me do everything everyone tells me to do with no question whatsoever."
Mute: characters who are recognized within the game world as people who are incapable of speaking
Secretive: these characters are a step up from mutes in complexity in that they are essentially predefined but are left with space for the player to insert his or her own thoughts and motivations simply left unsaid and thus "secret."
Reactive: protagonists whose actions are assumed by the game's scripting in spite of having no lines or dialo options. This the character technically speaks, and other characters in the world react to the player as if they have spoken, but the words are never actually shown or heard.
For those of you who look forward to writing scripts of video games, this is something to consider. What will your game stand for as far as the opinion of the protagonist? Is it really all that important to know?