Mass Effect lead producer, Casey Hudson, wants his series to be an actual trilogy rather than three games bodged together and followed by numbers.

He tells journalist Matt Peckham, "...one of the really big things we're trying to do that I think has never been done in this way before is tie together a trilogy of huge games where the entire story is one thread that's told by the player. All of your decisions and choices really start to snowball over the course of the trilogy because it's picking up the entire record of how you've played, from the first moments of the first game all the way through to the ending of the third game. In that instance"

So, how's that going to work? "...it was always the plan to be able to import your character, therefore we included all those variables in the save game. We try and work the trilogy story from both the high level and the detail level...

"The save game has every variable that you've set as a player, and as we delve into the detail levels of things like actual words that are spoken, art that appears in levels, sounds and music and subtle things as such...those can all be looked at, and how they comprise the world of each sequel can be affected by your choices in the prior ones."

There you go. Sounds BIG.