Space Marine 2 Patch 15.0 Adds Chaos Faction, Endgame Mode, and Tactical Rework

Warhammer 40,000: Space Marine 2's Patch 15.0 is one of the more structurally significant updates the game has received, touching faction representation, endgame progression, class design, and cosmetic customisation in a single release.

What changed

• Chaos in Siege Mode: For the first time in the game, players can fight as Heretic Astartes in Siege mode, alongside Cultists and a Helbrute, against both Tyranid and Loyalist forces.
• New Siege Map — Hive: Set in a Hive City on Avarax, the map tasks Heretic Astartes with defending key locations and performing rituals while fending off two enemy factions.
• Crucible Mode (PvE endgame): Described by the developers as "our first true endgame activity," Crucible is restricted to Level 25 classes, launched via PvE Operations, and uses a separate matchmaking pool. Players apply self-imposed Penances to increase difficulty in exchange for Crucible XP and unique cosmetic rewards. The Lamenters armour set is unlocked through progression here; rewards are stated to expand over time.
• Tactical Class Expansion: A full perk rework offering options around dual primary weapons, Gun Strike, and close combat, plus an expanded melee weapon arsenal for the class.
• Trials of Resolve #3: New Ordeals centred on Vanguard and Heavy class challenges, with PvP and Siege game modes included.
• One-Handed Thunder Hammer: A new weapon balancing single-target and area attacks, built around an accumulating charge mechanic for empowered strikes.
• Wargear 2.2: Separate customisation slots for tabards and cloaks, the ability to paint them, and an extended cloth colour list.

Taken together, the patch meaningfully expands what long-term players have to pursue, while the Chaos addition reshapes Siege mode's faction dynamics in a way the game hasn't seen before.