I picked up my copy of Black Crusade today after a session of D and D 4th edition. I ordered the GM screen and now i'm wondering... is there a sourcebook that is very useful for this rpg from the other lines?

Like the Grey Knights one or another one? A book that really adds a lot of critters/foes/substance without a need to convert (much or anything)

It really depends what direction you want to take your campaign in.

If you are setting it in the Koronus Expanse, Calixis Sector or the Jericho Reach books from the relevant line would be highly usefull.

If you want ships to play an active role in a campaign, you will need to pick up the RT basic book at a minimum, and Battlefleet Koronus would also be highly recomended.

Disciples of the Dark Gods from the DH line could be used as inspiration for groups for the party to work with.

Any of the monster books (Mark of the Xenos from DW if you have a lot of CSM's in the party, Creatures Anathema from DH if they are predominantly human) could be usefull, but they will require work due to the changes between the rules of the various lines. Fortunately BC has a section in it about how to adapt the material.

For me if I was setting a campaign within the Screaming Vortex and I was allowed three books from any other line I would choose the RT basic book, Into the Storm and Battlefleet Koronus. Ship rules (and stats for a lot of chaos ships), vehicle rules, lots of new equipment (Infamy and Aquisition from RT are an almost identical mechanic, making the two overlap nicely), new psychic powers to throw around and info on the part of real-space that any group of heretics leaving the vortex are most likely to come across (the Maw, Port Wander, Footfall, the stations of Passage etc).

Note as well that if you are after expanded psychic powers, the DH line uses a completely different mechanic than the other 3, making it very hard to adapt.

So the 2 creature sourcebooks will both need to be 'converted'?

Those 3 Rogue Trader books alos have some useful 'npcs' in them?

Church of the Damned have Sister of Battle Palatine and celestines listed. I'm still reading threw Blood of maytrers but alot of church-related NPC's are listed thier too. The Imperal Creed makes natural enemies for a Chaos Party. I was realy surprised they were not listed as enemies you could run into. I've been still trying to figure out if thier is a book that lists them more complety.

Besides that two monster books are great, since Genestealer cults and Orks always make good enemies no matter what side of the Imperial/Chaos divide you sit.

Personally I think Rouge Trader Core is a must since it gives you the rules for REAL ships. (Instead of the "plot convince ship"). It also lists some more"human friendly" enemies. (I feel Rouge trader PC's are closer in power level to BC then most DH PC's.)

Frozen Reach is a good buy if your getting the rouge trader core, since it lists Rouge Trader Balenced Orks that will be easier to convert to BC.

Hope this made sence.

@.@

For now I ordered the Deathwatch: Xenos addon for the formidable critters and the Ordo Malleus one. (I have a Grey Knights force and the Ordo Malleus/Grey Knights should be the 'ultimate' endgame foes more or less)