Players to get DLC achievements

With the missions I am hoping to get the couple single player achievements that I missed in my play through, does that count as achievements in DLC?

How many of the events required purchased DLCs - eg FON map pack?

Is it possible for players who did not purchase any of the DLCs to get the achievements?

In my opinion i think the achievements should stay normal with the game itself "Unless" the player decides to download a DLC for that game then they should update the achievements for that players game and make it uncompleted.

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But if the player has not downloaded any DLC i don't think it's fair to add the DLC achievements into the game since the player might not want to buy them or might not be able to afford them.

Ok I am in the same situation ALMOST. I want some gears achievements, but all friends have sold gears or traded it for whatever, simple point is I need three players. I only need a couple of chapters on 4 player co-op achievement. I also need some ppl for
horde dlc pack achievements and other dlc achievements.

So if you own the dlc and wanna get achievements or you wanna jus play horde or campaign FR me or shoot me an Iinv.

GT: WiNNTTeR

Say what you will, I shall only get this if achievements are applicable. If it was single player it would be different. But for me this is the kinda dlc where no achievements are given and so no purchase from me.