Steam adds achievement sets to group game achievements by developer-defined categories

Valve is rolling out a new Steam feature called achievement sets, which lets developers organize achievements into groups for a base game and its DLCs. Players still earn achievements by playing normally, with no changes to how they are unlocked. When browsing unlocked achievements, Steam will split the long list into these developer-created sets. Each set has its own progress bar, and completing one earns a visible "set complete" trophy. The change is intended to make it easier to track completed achievements and spot related ones to pursue next.