Valve is introducing a major new feature for Steam achievements called « achievement sets » that lets developers list different groups of achievements for a base game and DLCs.
« In games that support sets, you still unlock achievements by playing the game as usual, » Valve says. « But when you browse what you have unlocked afterward, Steam will break the long list of game achievements into the developer-created sets, making it easier to see what you have completed and to find other related achievements you can unlock next. » Achievement sets have their own progress bars, and if you finish a set, you’ll get a « set complete » trophy that’s visible …
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