Steam's Achievement Sets beta aims to stop new content breaking your completion status
Valve is beta testing Steam Achievement Sets, a feature that lets developers group a game's achievements into collections.

Valve is beta testing Steam Achievement Sets, a feature that lets developers group a game's achievements into collections.
The short version
- That's why developers can now specify the number of sets and the purpose of each "to match their game's specific needs", so one game might group its achievements into single-player and multiplayer groups, while another could use eight class-based sets.
- Players still unlock achievements as usual, and Steam then sorts what they've unlocked into the developer-created sets, which Valve says makes it "easier to see what you have completed and to find other related achievements you can unlock next".
- Each set has its own progress bar, and completing one adds a "set complete" trophy to the player's profile.
What happened
If new achievements are later added to a set, completion is "preserved". Developers can also create new sets as a game grows, which Valve says makes it "easy for returning players to see what new things they can unlock, while also preserving their prior completion status until they play again".
Why it matters
Base Game sets "contain achievements that can be earned by all players who play a game", with progress and trophies shown in blue, while DLC sets group achievements that can only be earned once additional content has been bought and are shown in purple.
Summary by Nerd News Network. Read the full article at Eurogamer via the links above and below.
