Thanks to those achievements being pretty glitched at the moment I didn't get the "Wings of Liberty: Hard 5/10/15/20/25" achievements by replaying missions on Hard difficulty after completing them in Normal difficulty.
I read that you have to restart a new Campaign and never change difficulty level throughout the whole play, which I am willing to do. But I wouldn't like to restart it twice (one time in Hard difficulty, and one in Brutal), so I am thinking of restarting it directly in Brutal difficulty.
Can anyone confirm that completing missions in Brutal difficulty not only counts towards the "Wings of Liberty: Brutal 5/10/15/20/25" and "Liberty Completionist: Brutal" achievements, but also towards the "Wings of Liberty: Hard 5/10/15/20/25" and "Liberty Completionist: Hard" ?
Best Answer
Yes. Any achievement, any achievement, that has a difficulty requirement as part of the achievement can also be completed on a higher difficulty. This means that (if you're good enough) you can get all of the Wings of Liberty Mission achievements on a single playthrough.
E.g., for the Red Lobster achievement, you can taunt the Brutalisk into the lava on Normal, Hard, or Brutal -- you don't "have" to be on normal (despite the listing to the contrary)