Has anyone used any other systems to effectively play as Space Marines in the 40k setting? Just curious if so what system? And how did it compare?

Black Crusade does well- I prefer it, in fact, because of the strictly regulated rate of Fate Point gain and the altered traits. Limited hacks to the archetypes are required, of course.

Speaking of hacks, Apocalypse World can be tweaked for 40k without too much difficulty.

Black Crusade does well- I prefer it, in fact, because of the strictly regulated rate of Fate Point gain and the altered traits. Limited hacks to the archetypes are required, of course.

Speaking of hacks, Apocalypse World can be tweaked for 40k without too much difficulty.

Agreed, the newer rules in BC and Only War make things far more balanced at times. The better way attacks are handled (bonuses to single attacks, penalties to multiple), the talents and traits have been reworked and many now make sense or have been refined, it eliminates the silly multiplier on unnatural characteristics in favour of fixed additions, psychic powers now have tests again to manifest rather than just simply passing a WP test.

I was thinking more along the lines of trying to run it using a non percentile based system. ie D20 or shadowruns system, maybe palladium, heroes unlimited could be possible.

Apocalypse World is about as far from a percentile system as you can get. Check it out here and here . It tends to emphasize story and personal relationships over rules and crunch- cinematics and drama over rules and gear-porn.

You could also run a 40k game using the Shadowrun system. Squats are already included, and minor adjustments to the Trolls or Orks would make decent Astartes.

Magic librarians, drain would be perils of the warp...what it would be missing is horde combat. Which is something I love in deathwatch.

Personally, I like the 3d6-based Dragon Age RPG from Green Ronin. It's very rules-light and I felt it was a welcome change from the usual trend of ever more complex systems - especially since it's very easy to modify (I tried a Mass Effect total conversion here ). The Stunt mechanic (rolling doubles generates Stunt Points to "purchase" special manoeuvres/bonus effects with) makes sure that combat remains entertaining even though combat basics are incredibly simple.

No Horde combat included (yet; supposedly Set 3 of DARPG will offer something there), though it shouldn't be too hard to just make up something from scratch.

I have chatted with one of the writers of dead reign, paladiums zombie game. And he has sent me rough rules he has been working on for that game to look over.... Heroes unlimited looks like it could be a very awesome rule set for 40k deathwatch, with some house rules thrown in.

My first try at 40k role playing was using the Omnigon system, an indie game from the early 90's. It played out ok, but my group never went back to it. It is still available (cheap) at Paizo.

We used Savage Worlds for a Rogue Trader campaign once. We used space combat and profit factor from the core rulebook, but the group was used to SW and didn't want to learn a whole new system right away. Given a year to let it sink in, we did finally try out RT with FFG rules and had ourselves a blast. Still, the SW game was fun. I'd think it would work for DW, but it would be more difficult for things like squad modes. I think you'll find the FFG rules fit the whole genre better.