Necromunda’s rules are tricky — here we explain Gyrinx’s philosophy, and the decisions we’ve made.

Sprawled across dozens of rulebooks, PDFs and White Dwarfs, Necromunda’s Rules As Written (RAW) are not short of the odd contradiction or confusing ruling.

So how does Gyrinx fit in?

Our rules philosophy has three key points.

First: we’re not a rulebook. Gyrinx is a tool to help people use Necromunda’s rules with greater convenience, but you still need to get those rules from Games Workshop (who retain all rights with regards to their content).

Second: we’re not here to fix the rules. While compiling content, we did not attempt to tweak or balance things — no matter how tempting it might sometimes be. In time, we plan to add tools to help arbitrators integrate their own house rules into campaigns, but for now we’re just trying to represent the vanilla rules in the clearest and most consistent way possible. 

Third: Gyrinx is not the rules. Just because you can do something here doesn’t mean it’s necessarily legal in the game. Always check the original rule resources, and ask your arbitrator if you’re confused.

There are some areas where Necromunda’s rules have either changed, are directly contradictory, or are clearly erroneous (as in they don’t categorically wouldn’t work within the standard framework of rules). In these instances, we’ve had to make a call on what the appropriate response is. 

Generally, this has meant deferring to books over model inserts, and trusting newer resources over older ones. We always reflect the latest FAQ/Errata where relevant. You’ll usually find these can be overridden where needed.

Here are the choices we’ve made:

• Core Rulebook (2023) profile used for grenade launcher flares, rather than Book of Peril profile (which has the Grenade trait). [Note grenade launcher anti-plant grenades still have the Grenade trait, as per BoP.]
• Claim Jumpers carry power mauls (per Ruins of Jardlan and Halls of the Ancients), rather than power picks (per fighter card included with Claim Jumper model).
• Hardcase Cyber-mastiffs listed as 130 credits (per Vaults of Temenos), rather than 70 credits (per fighter card included with Scrutinator-Primus Servalen model).
• The M3 Sump Beast profile (present in White Dwarf ‘Outlaw Brutes’ article, but supplanted in Necromunda Apocrypha book), has been maintained.
• We have maintained the Backstab trait on the Insective Knife even though the 2025 errata update (which added Toxin) rendered it meaningless.

If you disagree with our decisions, or believe we have overlooked an error of this type, please do let us know via #content on Discord.