Like a point of no return in an RPG, the campaign of StarCraft II offers you some optional upgrades that you cannot change your mind on. Choosing one blocks out another, and while all of these upgrades are useful, some simply shine more than the others. Conventional wisdom doesn't apply if you're used to multiplayer, so use our guide to ensure that you don't end up regretting your decision and forced to replay the campaign for the research you'll need to handle Brutal difficulty!

Look no further than here for the StarCraft II - Campaign Research Upgrade Guide!