I've remained silent on this issue for far too long, but I can do so no longer.
While playing Fallout 4 and looking at an Achievement Guide, it was brought to my attention that some of the Achievements are mutually-exclusive to a playthrough unless you save-scum. Not only that, but other achievements are locked behind moral choices, but only if you pick a certain choice! That's not how Achievements should work!
Achievements should follow these rules:
1) A player must not be able to lock him or herself out of obtaining an Achievement. By the time you reach the end of the game, you should be allowed the option to return to all instances where an Achievement could have been obtained in order to reach 100% game completion. The obvious exception to this rule is games that are designed for multiple playthroughs.
2) No Achievement should require the action of another human to complete. It can certainly be an option, maybe in a game with online capabilities that someone could help you get an Achievement, but that can't be the only way. Humans are unreliable and untrustworthy and making others rely on them to get Achievements is only going to result in pain.
3) No more than 50% of a game's Achievements should be obtainable as part of completing the main story. No one cares about those ones! It's not "oh no, I had to work so hard to follow the neon signs down the path that the developers painstakingly designed for the lowest common denominator, I'm so glad I was rewarded for this", it's usually "oh... a consolation prize... yay..." It cheapens the Achievement brand, and it's just insulting. Sure, it can be handy to know how far you are in a game, sort of like announcing chapters in a book. However, you could just do what Half Life 1 did in the days before Achievements and just, you know, tell the player that they've advanced to the next part of the game? The only reason I could possibly see for not banning these (with the exception of an Achievement for completing the main storyline) would be so that you can check how far your friend has advanced through a game so that you can avoid spoiling what is to come next.
4) No hidden or vague Achievements. I shouldn't have to look up a guide to find out what I have to do for an Achievement let alone what the Achievement is. If they're hidden to avoid spoilers, find a way to write the description of what you have to do a different way. If this is hard, try hiring better writers.
5) If an Achievement requires the player to complete an action a certain number of times, there MUST be a visible counter to help the player track his or her progress. This is pretty self-explanatory. I should have to mentally tally how many times I do something or just keep doing something until I get the Achievement popup. The game is already counting for me. Why can't it just show its work? Lots of games already do this, it needs to be standard.
I propose that the governments of the world sign an agreement to make a Ministry of Achievements (or Department of Achievements depending on your government's terminology) that regulates all games their country publishes. Not only will this governing body work to ensure that the 5 Commandments of Achievements are followed, but they will also work to ensure that Achievements are challenging but not impossible. Hopefully this will permit the art-form to flourish and will prevent unscrupulous game developers from releasing substandard video games.
Please remember SPIRIT's 5 Commandments of Achievements the next time you're voting. Thank you.