Hi everyone,
I've seen some posts where there is a bit of confusion about the ability to get the best endings by only playing single-player, because if you don't play multiplayer (or the iOS game, Infiltrator) your Galactic Readiness stays at 50%.
You do NOT have to play multiplayer to get the best single-player endings.
Here's a bit of clarification:
Your ending(s) are determined by your "Effective Military Strength" (let's call it EMS for now) bar. Focus on that bar - that is your indicator of how well you will do in the end-game.
You can maximize your EMS just by collecting War Assets in the single-player game. There is a certain threshhold of these you would need to exceed (I can't get too specific) but I can tell you there are MORE than the required amount that can be gathered in the single-player campaign.
"Galactic Readiness" is a modifier you can improve by playing multiplayer. That is to say, if you play a lot of multiplayer, you will need less War Assets from single-player to fill up your EMS bar (ie it will balance out the requirements to account for you playing in both modes). Single-player game play does not impact that bar.
EMS = success. EMS can be maximized via collecting war assets alone, even if your Galactic Readiness is 50%.
