Primaris Space Marines are effectively enhanced variants of existing Imperial Space Marines. They may be part of any Space Marine chapter.

Primaris marines represent the next generation of superhuman warriors created by the Imperium; standing apart-yet-the-same as their older Space Marine battle brothers.

Wielding the latest Imperial innovations in both Space Marine armour and weaponry, Primaris are attached to existing Adeptus Astartes chapters in Warhammer 40k, needed reinforcements to the dwindling chapter might. Often turning the tide of conflict and providing well-needed replenishment to a beleaguered chapter.

Primaris Astartes focus on quality over quantity, reflected in their access to superior arms & armour, but their armoury still offers a variety of tactical options as laid out in the Space Marines’ equivalent to the Art Of War, Codex Astartes.