so i was wondering how compatible is death watch and black crusade with 2nd edition dark heresy sounds like they will not get an update and i would really like to include the options from both of those core games with 2nd edition like you could in 1st edition.

What kinds of 'options' are you talking about?

If you mean weapons and other items; in the few side-by-side comparisons I've done between DH2 and BC (and also OW), they've been identical or at least very close.

DW, on the other hand, seems a bit further removed.

mainly npcs, character options, and weapons

so i was wondering how compatible is death watch and black crusade with 2nd edition dark heresy sounds like they will not get an update and i would really like to include the options from both of those core games with 2nd edition like you could in 1st edition.

The WH40KRP line breaks down into two generations: the first generation includes DH1 , RT , and DW , while the second generation is BC , OW , and DH2 . Within the generations, the differences are mainly relative power levels, with a few miscellaneous odds and ends specific to each setting. Between generations, however, there are more pronounced differences. If you are looking to poach NPCs/monsters from different systems (I do this myself all the time), the biggest difference (aside from power level, which can be scaled with the PC's current experience level) will be in terms of Skills. The 2nd generation games use a condensed skill list (Hide, Silent Move, and Shadowing are grouped together as Stealth, for example), which means stuff ported over from 1st generation games will need some tinkering to match the new Skill options.