Is there a legitimate method for unreleased DLC unlocks?

I see that there are a few people who have unlocked a bunch of achievements for unreleased areas of the game on PC. Is there an actual way to get these through the game, a glitch that granted them, cross-play save games from xbox one, or cheating?

e.g. An achievement that requires Halo 3 which isn't released on PC has 3 tracked gamers.

No, it is not currently possible to unlock those achievements right now. If you do come across someone that has them, please report the gamer so we may investigate.

The achievement list on xbox live is the same, that is to say it is shared. Somebody could unlock achievements for other titles in the collection, then log in to the game on Steam. That might trigger unlocks for steam achievements.

Would be rather zealous to report that.

Spartan9209 said:In short = Yes, if you play Halo: The Master Chief Collection on Xbox One using the same Xbox Live account.

With all of that in mind, achievement progress is transferable between Xbox One, Windows Store, and Steam versions as noted in the following support article on HaloWaypoint.com: MCC PC Crossplay & Cross-Progression

Reporting any gamer for having unlocked achievements in games not currently available for play on the Steam version is just going to cause a major headache for the Investigation Team when they need to reverse any action made on those accounts.



You can purchase Halo: The Master Chief Collection for Xbox One and unlock achievements from all 6 games in the collection (see the Xbox Live achievement list on TrueAchievements.com).

On Xbox One, the following games are playable (as of 3 December 2019):
- Halo: Reach (premium DLC released 3 December 2019)
- Halo: Combat Evolved Anniversary
- Halo 2: Anniversary
- Halo 3: ODST (premium DLC released 30 May 2015)
- Halo 3
- Halo 4


Halo: The Master Chief Collection on Windows Store shares the same list of Xbox Live achievements with the Xbox One. However, the Windows Store and Steam versions contain the following playable games in the collection at the moment (future titles to be released in narrative chronological order):
- Halo: Reach (as of 3 December 2019)
- Halo: Combat Evolved Anniversary (as of 3 March 2020)
- Halo 2: Anniversary (as of 12 May 2020)
- Halo 3 (unreleased)
- Halo 3: ODST (unreleased)
- Halo 4 (unreleased)



So in short, here is what you need to unlock achievements in any of the games not released on Steam (including, but not limited to Halo 2: Anniversary, Halo 3: ODST, Halo 3, and Halo 4):
1) a 64-bit Windows 7 PC (or newer) with a purchased copy of Halo: The Master Chief Collection from the Steam Store
2) an Xbox Live account
3) an Xbox One console (Xbox One, Xbox One S or Xbox One X)
4) and any one of the following
- an active Xbox Live Game Pass (console) subscription
- an active Xbox Live Game Pass Ultimate subscription
- a purchased copy of Halo: The Master Chief Collection for Xbox One (disc or digital)



Notes:
* You can install and play Halo: The Master Chief Collection for the duration of your Xbox Game Pass subscription. Alternatively, you can purchase a copy of Halo: The Master Chief Collection for Xbox One (disc or digital) if you do not have Game Pass.
** Windows Store version requires a 64-bit Windows 10 PC.
*** Steam version requires a 64-bit Windows 7 (or newer) PC.

There are some achievements that will unlock on xbox live but not on steam, because the team likely didn't think they could be unlocked or because it's a bug. I have four achievements on XBL but not on Steam.

Given that some people would have done it if if were possible, I doubt achievements from other titles can be unlocked on steam until they are added to the collection.

To further add on this, MCC-PC when it launched had a weird issue where for some users certain Steam achievements would unlock on Steam despite the Steam version of that game having never been released to begin with.

In fact, to further complicate this, you can buy 1 Halo MCC title (let's say halo 3) for $10 and if you already own a Xbox One or the Win10 version either through game pass or just by owning the entire game itself, by playing the game on Steam even if you don't own all the games on Steam, any achievements you got in Halo 1, 2, ODST, on either the XONE or WinStore will automatically unlock on Steam regardless of the status of whether or not you own the other Halo titles on Steam.

Another issue was how when Halo Reach 1st released, a lot of people that had unlocked certain H2A achievements on the XONE were unlocking them on Steam as well despite the Steam version of H2A having not been released, this also happened with a few ODST specific achievements. I'm assuming the same thing happened with Halo 3 here as well but it must've been a one off thing at best. MCC in general has always had weird achievement problems and having it release on PC hasn't changed that.

Either way, Halo 3 has officially released on PC by now from the time of this post so it's a pretty late issue to talk about by now. Just consider it if you see people having unlocked certain Halo 1, 2, 3, or 4 achievements before they officially launched on Steam. Always try to check what there Xbox profile is and see if those same achievements were unlocked on XLIVE years ago and it could very well be just that. If not, report the account and it should be dealt with swiftly.

All MCC Xbox achievements are directly tied to MCC Steam achievements and will unlock in huge amounts with each games release if said person has unlocked those achievements already on the XONE.