[W40K]Looking for tips for cross-over campaign (Deathwatch/Dark Heresy/Rogue Trader)

[Zid]

I have an idea for a cross over campaign that could and should involve several different characters. Does anyone have an idea what level the other characters need to be to be on approximately the same level as a Deathwatch starting character?

[The Glyphstone]

Rogue Trader says a Rank 1 Explorer is roughly equal to a Rank 5 Acolyte. A Rank 1 Space Marine is equal to a Rank 8 Acolyte, the highest you can go without Ascension.

But honestly? The only tip I can give is 'don't'. It sounds like a cool idea on paper, but while the three lines are mechanically compatible, playing them side-by-side will cause all manner of headaches.

1) DH characters start so far behind the others that their massive XP allotment compared to even a Rank 1 Trader character makes their stats go through the roof, they have very little to buy except stat increases within their advancement charts.
2) The Rogue Trader characters won't have the stats or skills of the Acolyte, but the ease with which they acquire equipment makes them easily capable of rendering the other characters completely irrelevant in a lot of situations. The 40K RPGs are all about stacking bonuses, and Rogue Trader characters stack bonuses better than anyone else.
3) A Space Marine, with effectively no XP to spend, will still singlehandedly annihilate any combat encounter capable of threatening the human characters, because unlike Black Crusade, Deathwatch and its predecessors weren't intended to be balanced against each other. They'll be utterly useless in any non-combat situation, and most roleplay encounters, and forced into Solo Mode all the time which weakens their utility further.


If you absolutely, absolutely must do this sort of thing? Use the Black Crusade rules. Throw out all the Chaos fluff, make characters using the best-equivalent Archetype (renegade for a Guardsman/Arch-Militant, or Legion Sorcerer for a Librarian, etc.), then use the regular Mutation/Insanity rules instead of the special Evil Mutation rules. You'll still have some balance issues in combats between Marines and Humans, but the gap is greatly narrowed, and now everyone can contribute somewhat.