Shadow War & Necromunda Cross-play

Are Shadow War: Armageddon and Necromunda:Underhive Cross-Compatible?

Games Workshop has released two game systems that share a lot of the same DNA: Shadow War: Armageddon and Necromunda: Underhive. These games are very much based on the old school Necromunda rules with some updates and tweaks so that got us thinking here at BoLS – Are these two systems able to Cross-play? It’s a bit more complex than a simple Copy+Paste – but we think it’s doable…maybe.

The Systems

The First major hurdle is which ruleset are you going to convert to – would you want to convert Shadow War: Armageddon into Necromunda: Underhive, or go the reverse route? Personally, I think I’d like to mess around with the Necromunda Ruleset currently, so lets just assume we’re moving Shadow War over to Underhive. For the purposes of our examples, we’re using the free PDF for the Genestealer Cult which you can find from GW HERE.

The Stats


Both systems use the same basic stats – but if you’re a vet you’ve spotted a big difference between the WS/BS stats. Shadow War uses the comparative system and a Chart – Underhive uses the newer 8th Edition style WS/BS. Same with the Initiative stat. The other core stats (Movement, Strength, Toughness, Wounds, Attacks) are all pretty much the same. And then we hit a hiccup with the 2d6 Stats like Leadership, Cool, Willpower, and Intelligence.

Leadership in the games function like inverses of each other. In Shadow War, you want to roll under – in Underhive, you want to roll over. But they are both based on 2D6. Keep in mind that on 2D6, there are 11 results. We can count how many results would be a
“pass” for each style. For example, if you have a leadership 9, there are 8 results out of 11 that would be a pass. But if you have a +5, then you’d have 7 results out of 11 that would be a pass. So in the example stat lines above, if we were doing a straight conversion, the Neophyte leader would need a Leadership value of +4. Simple enough, right? But, you also have to take into account the statistical probability of rolling those results. Now, I’m not going to get into all that because it’s a lot of math…but I think that is something that could be worked out.

But I the last 3 stats are going to be a problem. That would probably take a designer who knows both systems a week to work out, but I think your average stats of 7-ish would be a good starting point.

Points Vs Credits

I think this (overall) would be a pretty straightforward conversion. Just replace Points with Credits and you’re good to go. There might be some outliers but it’s a good starting point.

The Skills


Each Warband in Shadow War has a skills table (thankfully). Unfortunately, in Underhive, they don’t exactly line up. It’s 7 skill tables vs 8, and some of them have been renamed. Now, the Leadership skill tree could be designated for Gang Leaders only. I think that makes sense.

For the rest of them, 5 of them have direct analogs so I think that works pretty well:

Agility = Agility

Brawn = Muscle

Combat = Combat

Ferocity = Ferocity

Shooting = Shooting

However, the last couple don’t line up exactly:

Cunning/Savant from Underhive and Stealth/Guerilla from Shadow War.

For those, I think you’d have to go skill by skill and work out the analogs and what those would be. It’s doable – but time consuming.

The Wargear

As we’ve been poking around at the gear, again, we think there are some obvious analogs – Lasguns are still Lasguns. If Underhive has a new stat line, we’d recommend using those. The problem is when you get into the more “Exotic” weapons like a Mining Laser for example. Sure the stats are close enough…but there are other things that might need to get worked out. Again – doable, but time consuming.

Oh and don’t forget to think about things like ammo rolls and damage dice for all that Wargear either. That might throw a wrench in the conversions.

The Verdict

If you skipped the first paragraph then this might be a surprise to you – but we do think it’s doable but you’re going to have to house rule a LOT of stuff. Aside from stat-line conversions, you’d have to create 3 new stats for all the different Warbands in Shadow War and you’d have to adjust all the skill tables as well. And don’t even get us started when it comes to special rules and hiring other Specialists to your Warband/Gang.

Cross-playing Shadow War and Underhive is a possibility, but it would take a lot of leg work to make it happen. If you have access to both systems you could figure out it – I’m sure there will be fan-made conversions for the systems. Personally, I want to dig into this topic deeper simply because I want to play with Genestealer Cultists in Necromunda Underhive as soon as possible – and I don’t want to wait for the “Outlander” expansion to come out to do it!

Conversely, I could also just play the original Necromunda with the Shadow War rules as they are pretty dang close to begin with…But the Close Combat of Underhive is so much cleaner!



If you could convert a Warband from Shadow War to Necromunda, would you want to do it? What crew would you run? How long do you think it will be before we get Conversion Charts and do you think GW should make it happen?

  • Silverbeast

    And where is the XP system? Has it been gutted out?

    • I_am_Alpharius

      The Ganger advancement rules are included in the Gang War supplement.

      • Silverbeast

        Ok, then why BOLS post this article like this?

        • John Henry III

          I’ve tried responding to his post twice already but aparently BOLS doesn’t like it when we call their articles… well lets just say it rymes with ick ate

  • I_am_Alpharius

    The real question is: Why would you want to? Seems a tad futile to cross them over. Frankly a lot of effort for not much benefit.

    • Me


      • I_am_Alpharius

        Rules for that kind of thing will come quick enough. Heck, wouldn’t be surprised if they do Genestealer Cultist as WD exclusive rules, in December. Or they could put a simple roster in the Necromunda Legends pdf that is going up on the Necromunda website on the day of release.

        • Moonsaves

          Chaos Cultists, Genestealer Cults, and PDF Troopers would be easily done.

        • Me

          I think “quick enough” is relative to the patience of the person waiting…

          Of course we all know that the people who frequent these forums are the most patient people on the planet… ಠ_ಠ

    • SilentPony

      Just wait until the 30k crossover and House Escher has to take on Angron and 3k worth of Rampagers and assault squads

      • benn grimm

        Sounds like you’d need a lot of gang boxes for that match up…

        • SilentPony

          I’d actually love to play that match with my 30k Death Guard. Just full on trench warfare!

          • benn grimm

            I’d love to be wealthy enough to give you that match…;)

    • benn grimm

      Because some people have invested in Shadowgeddon, it uses the old Necromunda rule set, is essentially the same game and would have made a lot of sense?

    • NNextremNN

      Why not? Also it could expand player base for both systems instead of limiting and separating them.

    • Fredddy

      It would be fun to continue SWA with a supported ruleset, but more important is that compatibility with SWA would mean compatibility with the huge amount of existing old Necromunda material (official and fanmade ones).

    • For fun, it’s not like there aren’t about 100 different homebrew lists for the current Necromunda systems, there will be again lol

  • benn grimm

    If you play the original Necromunda then yes, otherwise it’s gonna be difficult. Usual joined up thinking from gw.

    • memitchell

      C’mon, Man. You know they don’t want you simply playing original Necromunda (either with the original Necro rules, or Shadow War rules).. They want to to buy New Necromunda. So, it’s a new game. And, different enough from New 40K that you can’t just play it with those rules. Give them credit for knowing to make something so different that people will want to buy it, instead of recycle it. There is evidence of Intelligent (Intentional) Design here.

      • benn grimm

        Kinda cynical, but I’m sure you are 100per cent correct.

        • memitchell

          I don’t mean to sound cynical. I don’t love it, but I do see the logic in it. And, I’m sure it’s all about the Sector Mechnicus terrain. Instead a another box like Shadow War, full of SM terrain sold at a discount, they very cleverly make the initial offering a game played on boards. And, if one is so inclined as to want to play the game on 3D terrain, and play the campaign, they sell a separate book. And, the terrain. Marketing-wise, it’s a kinda weird mix. Especially since the separately sold gangs are reasonable priced.

          • benn grimm

            The gangs are what’s saving this release for me, they are pretty fantastic and as you say, also reasonably priced. The rest I find kinda dubious tbh. To make a game incomplete, incompatible with other similar recent releases, in order to sell more box sets and books seems not only slightly shady, but also quite possibly self defeating. I do hope they haven’t sabotaged themselves, I’d like to believe the Underhive just got a new lease of life and will be alive and kicking for a while to come. Time will tell.

          • memitchell

            My true scandal is I like boardgames, too. I’m intrigued by the Under-the-Underhive sewer setting. But, I am skeptical about how that will play as a miniature game, versus a boardgame. Plus, I want those sewer broads for evil Space Hulk purposes, and the like.

          • benn grimm

            More ‘hulk boards are always a good thing, can’t say I’m not tempted.

          • Could run the old Spcae Hulk-Necromunda scenarios where the Ultramarines get sent into Hive Secundus vs the GS Cult

  • memitchell

    “If you could convert a Warband from Shadow War to Necromunda, would you want to do it?”
    “What crew would you run?”
    “How long do you think it will be before we get Conversion Charts”
    If we do, how long do you think it will be before New Necromunda becomes poor man’s 40K, and gets shelved?
    “and do you think GW should make it happen?”
    The campaign is what makes the game. Adding in 40K detracts and distracts from the campaign. So, no.

  • denzark

    Different stats, different dice. Sounds like a no then…

  • ROMKnight

    I’m annoyed Shadow War had such a short run… I’d like to see more support for it… I won’t be getting into Necromunda. If you can adapt the more complex campaign rules to Shadow war though? I’d probably give it a look.

    • Maybe we’lol get lucky and GW will do a second ed of shadow war, they’ve always done some kind of skirmish rules for 40k, and the new Necromunda would work well as the core rules (plus are similar to the 8th ed rules superficially, unlike shadow war)