So I ask on behalf of my GM. We are currently running a Deathwatch campaign that will lead us to an opportunity to become renegades. All the players are up to it. So we are looking for a transition rules into a black crusade setting.

Any advice on how to tackle it?

There's a few examples In the black crusade book.

Or instructions on how to do it.

Are you the loyalist pigs us heretics will be fighting?;D

To be frank I have several conversions between a few WK40k systems behind me and the best way to tackle the problem was to recreate the characters from scrap. You might have to adjust the XP here and there but this prevents SO MANY problems that I hardly consider any other way of conversion. This way you might lack a talent or two but in the end you are sure to have a character that works in the intended way of its rulesystem.

(Note: You might want to allow your players to create their characters with an alignment for spending all XP undivided might not be a good idea.)

I'm with Moep on this one. The books may use similar systems (in that you play all these games with a d100), but still they have some unique rules, some rules that just work differently, and most of all a different "powerlevel" with enemies and equipment statted for a different type of player character.

A bunch of DW Marines with original rules would just wreak havoc within any ordinary DW campaign. I point towards the "one on one vs a bloodthirster" thread to remind everyone of how lulzy squad modes can be.

However, the games are similar enough that you could create BC characters whose general style is nigh-identical to those DW characters by way of using either the same talents, or those that are "close enough".

The official rules for transferring characters over when they reach 100 corruption are on page 281 of the BC main rulebook but the ideas above are very good.

One of the biggest sticking points is stats strength and toughness. They are way more expensive for DW marines but they also come as a twofer one because of unnatural rules. That is completely lost in the conversion.

Thanks for all the feedback!