Originally Posted by azarhal 
You can get enough "war assets" in a single player playthrough to see 3 endings with save and reload. There is a 4th ending that can only be seen if you do a NG+ (new game plus = replaying with the same character).
The game guide mention 6 endings though…
See, that's what bothers me. Crossover multi-player/single-player marketing is fine… such as a "widget" that's only available in multi-player once you've finished single-player or vice versa. But actually limiting the number of available game endings in a single-player game because I don't choose to play multi-player feels, again, like EA pushing me into something.
I know that if I ever play ME3 (and jury is out on that and waiting on real reactions from folks on this site), I will almost assuredly never play the game in multi-player, something I only do with my wife or very good friends, and my wife and very good friends do not play Mass Effect. So, now I'm being penalized for that choice.
Rule 1: don't limit gameplay based on participation in activity A. Instead, reward users with special, additional widgets based on participation in activity A. If they wanted to give me a special "gun" because I played a bunch of multi-player I'm fine with that, but don't limit the actual, potential ENDINGS TO THE STORY… </endrant>.