I started DMing a Black Crusade campaign to some of my friends some time ago and other guys I know started playing Dark Heresy and Deathwatch. Yesterday, they asked me if we could make a campaign where their Dark Heresy and Deathwatch characters go up against the Black Crusade characters from my game. I think this idea is pretty good and it makes for interesting story possibilities and gameplay scenarios and I would really like to try and make a campaign like that. However, I don't know if the rules and systems from Deathwatch ,Dark Heresy and Black Crusade can work with each other. For example can a Space Marine character using Deathwatch rules fight a CSM who uses Black Crusade rules? Would that be a fair fight? And even if they could fight I'm sure I would run into some more problems down the line. I have never seen a Deathwatch/Dark Heresy game. I'm really interested if this idea could actually work.

Yes, this can in fact work, and there is even a (brief) section in the Black Crusade book detailing how one might go about this.

Assuming that the Black Crusade character/s are starting off at 'level one' (going through character generation normally, in other words) then player characters from Death Watch and Dark Heresy would start off with 7,000 (or 8,000 if the Black Crusaders in question are CSM as opposed to regular ol' heretics) experience to bring them up to a similar power level. As far as weapons go, it would be best to use the equivalent statlines in the Black Crusade book for balance purposes and whatnot. Should your Dark Heresy character be playing a Psyker of some sort, use the rules for casting psychic spells detailed in the Black Crusade rulebook.

Thank you for your answer. Somehow that small section slipped past me. But I will have to find it now. I think I kinda understand how to do this . My biggest concerns were the balancing issues and which rule book to use. So thanks for helping me clear that up .

It really doesn't say much other than about how much XP to dole out to characters in the other systems upon character generation. Keep in mind though that the Dark Heresy characters will most likely have the most talents/skills/etc. when starting out this way as they get more experience than any other character [iirc, a starting Rogue Trader character starts off with around 4,000 xp assumed to have been spent after coming out of character gen and blowing the last free five hundred on whatever they deemed necessairy, so they only get 3,000 additional. This means that the DH player gets a full 7,000 to spend (go go assault veteran!) Of course there's a chance I may be wrong on this, but it seemed to be balanced well-enough for my group.]

The only problem I see is for a DW SM that starting at 13k is far behind a CSM from BC or any other character for that matter. The Chosen from BC (which covers pretty much all but librarians duties) needs only 2k more xp to be have all the abilities a DW counterpart has (with the sole exception of DW training special ability).

DH characters will definitely need to Ascended, but other than that it should work.

Do note, however, that you should be careful when putting players against players. For some reason, this can trigger all kinds of unfair behaviour in otherwise good-natured players.

Thank you for your help and for all the advice. You helped me a lot. I talked a lot to the DM of the other group and we managed to work out most of the things. He is a lot more experienced than I am and we came up with some pretty good solutions. I think I'll be able to run the campaign now (our first session is on Friday).

Lucius Valerius said:

Unless I missed it, CSMs in Black Crusade get neither a Solo Mode Ability (they get an Archetype-based ability, but it doesn't scale up like the DW ones) nor do they get the (quite powerful) Squad Mode options of a DW Kill-team.

However, I do agree that the higher the starting point of a WH40KRPG character across the lines, the harder it is for them to keep up once xp is added to bring everyone up to a certain point. DH characters are, ironically enough, the most skilled and talented characters you can make at 13,000xp.

HappyDaze said:

That is correct BUT on the other hand 5k xp worth in advancments are more then enough to turn a "rank 1" CSM into a very nasty enemy while a DWSM is just a rank 1. The CSM would have multiple attacks, increased parry and dodge, counterattack for melee and so on, you know the gist...

The only time a Deathwatch char is going to feel at all like a 13000 xp char, is if they have access to squad mode abilities. In particular, the only thing that I can tell justifies them being 13k is the reaction-based squad mode attacks; being able to pop off a lascannon shot as a reaction to an enemy's turn (which apparently can't be dodged, since reactions can only be used when its not your turn), for instance, is extremely powerful.