Steam Achievement Sets: will DLC undo completion?

Valve began testing Steam Achievement Sets on October 15, 2026, with a useful promise for achievement hunters: completing a set can remain part of your record when a developer adds DLC or more achievements later.

The catch is that this protection applies per set and depends on developers configuring those sets. Steam is not automatically reorganising every existing achievement list, so the feature does not instantly fix completion tracking across an entire library.

Will DLC undo a completed Steam Achievement Set?

Not when a participating developer puts the DLC achievements in a separate DLC set. According to Valve’s Steamworks documentation, a DLC set does not count towards completion of the base game or another set. It only counts towards a player’s completion if that player owns the relevant DLC.

That means a new expansion need not make a completed base-game set incomplete simply because the expansion introduces another achievement list. Valve’s Steam Client Beta patch notes summarise the intended result: “DLC achievements can be added via sets without breaking game completion.”

This is not a universal promise that all DLC achievements will be separated. Developers decide how many sets to create and what each one represents. Valve says sets could distinguish a base game from DLC or divide achievements by campaign, multiplayer mode, chapter, character class or event.

What happens when more achievements are added later?

Completion is also preserved when achievements are added to a set that a player has already finished. Valve’s Steamworks documentation states: “Once a player completes a set, it stays completed, even if you add achievements to that set later.”

The newly added achievements can still appear in the set; the change is that they do not revoke its existing completed status for that player. Completion is therefore being recorded per set rather than treated only as one changeable percentage across every achievement associated with a game.

Archived achievements no longer have to block completion

Achievement Sets also let developers archive time-limited or otherwise unobtainable achievements and sets. Valve says an archived achievement remains visible to a player who unlocked it. For someone who missed it, the achievement does not appear or prevent progress towards completing the applicable set or game.

This could help games with retired seasonal events, but the decision remains with each developer. Valve provides the archival option; it does not automatically classify or remove old achievements. The behaviour is described in Valve’s official Achievement Sets announcement.

The catch is developer adoption

All existing achievements begin in a game’s base-game set unless its developer assigns some of them elsewhere. If no additional sets are configured, players continue to see one achievement list rather than separate base-game, DLC or event collections.

Adoption does not require a game-code or Steamworks SDK update. Valve says developers configure sets in Steamworks, while games continue to unlock achievements with the same API names and calls. That removes the need for a code change, but it does not guarantee that publishers will revisit older games and reorganise their achievement lists.

What changes on Steam profiles?

The beta also changes how completion appears on profiles. The former Perfect Games tab is now called Completed, while completed sets can receive trophies. Valve also says completing any one of a game’s sets can make that game eligible for the Completionist Showcase.

That qualification matters when reading another player’s showcase. A game appearing there is not necessarily evidence that the player earned every achievement across the base game, all DLC and every optional set. It can mean that the player completed one qualifying set. Valve explains this eligibility in its Achievement Sets documentation.

Where Steam Achievement Sets are available

Achievement Sets are currently available through the Steam Client Beta and only in games whose developers have added support. Valve’s initial list included Portal 2, Team Fortress 2, Crusader Kings III, DREDGE, Forza Horizon 5 and PowerWash Simulator, among other titles.

In a supported game, the redesigned achievement page can show progress by set, filter achievements by set and lock status, display global statistics, and compare results with up to three friends. Valve demonstrates those features in its beta announcement.

Valve’s announcement does not provide a date for release to the stable Steam client. For now, the practical conclusion is conditional: if a developer configures separate sets, completed base-game progress can survive later DLC, new achievements and retired events. If the developer does not configure them, the existing all-in-one list remains.