What are the differences in styles of play for the various Warhammer 40k games?

Question

We're looking at starting up a campaign in the 40k system, using one of the following as a main set. It seems like the breakdown is:

1. Rogue Trader -- Ship And Crew Making Money
2. Dark Heresy -- Crew takes orders from NPC 'captain', used as do-boys.
3. Deathwatch -- Space Marines; the 'dungeon crawl' of the system, as social/intrigue/detective are de-emphasized in favor of "IN THE EMPERORS NAME!"

Is there any significant difference in the way that these various types play out? Any reason to recommend one over the other aside from their slightly different motivations / party makeups? Any one of these have a much more enthusiastic following than the other, for a good reason?

Answer 1

Differences in the way they play

Dark Heresy is probably the most similar to a traditional game in this regard. Because there is no default status quo, you can pretty much go in any direction imaginable without significant hand waving.

Rogue Trader does tend to lend itself to games that have some space combat/travel/exploration component in order to allow all players to contribute (not quite as bad as deckers in Shadowrun, but a similar problem).

Deathwatch really and truly seems designed for episodic play (though you could easily work in overarching plots). A lot of the rules necessary for longer play (insanity and corruption in particular) are very weak and not well developed and the mission-based structure essentially gives you the format for each episode.

Any reason to recommend one over another

I think each game really does bring something unique to the role playing experience. To some degree, these answers are quite subjective and could be modeled in other games, but the rich backdrop of the 40K universe really helps drive these elements home.

• Dark Heresy - Really encourages the exploration of the mythos and gives a GM a lot of opportunity to develop deep, intricate (perhaps even obtuse) plots with encounters that seem truly lethal and require cunning and skill to get through.
  [rich skills, winding plots, lower power level increases lethality]
• Rogue Trader - Out of the systems, this is the most interesting in a lot of ways in that it delivers on the promise of roleplaying in a Star Trek style without that silly Prime Directive. Players are fairly powerful and masters of their own fate, each highly specialized with something to do. Combined with the geeky attraction of designing your ship, I think this game has quite a bit to offer.
  [Star Trek-style exploration, deep character specialization, ship design!]
• Deathwatch - For many, this game will be the winner simply because it's Space Marines. While it does lend itself to combat-intensive sessions, FFG has done a good job of trying to give the marines some actual personality (although this personality is often hidden and only revealed in the solace of their own rooms). However, the mission structure has a similar appeal to the job layout of Shadowrun games and can really help get players moving. And of course I would be remiss if I didn't mention the very detailed combat mechanics and options which do allow for some fairly cinematic gameplay.
  [roleplaying hints for players, clear session objectives, interesting combat]

Any with a more enthusiastic following than another

I think it's safe to say that Dark Heresy has a larger following, but this is a factor of age. Otherwise, I think the vibrancy of all three games is pretty light outside of Fantasy Flight Games' own forums (though I did notice that the Deathwatch forum nearly has as many posts as the Rogue Trader forum at this point even with the year head start the game had, so it may be that Deathwatch will end up being the more popular game).

Answer 2

In Release Order

Dark Heresy

Mission Focused, Low-Power, and a mix of dungeon-ish and social interrogation.

Players being, by default, acolytes of some inquisitor. Which means investigations of Chaos infestations.

This is, in all actuality, the most flexible of the games, having the widest variety of character types. It can be used for a wide variety of low-power citizen-focused games.

Lethality level is moderate to high, depending upon gear, cash, and threats faced.

Rogue Trader

High Power, advancement focused.

Players can pick what their goals to some degree. Large portions of actual play are about gaining in prestige and wealth.

While there is limited potential for exploration type stories, the default mode in the modules are about military adventurism in a conquistador type mode, and making money by trade.

Lethality level is fairly low - PC's tend to have decent gear, and the threats are not overwhelmingly hard, usually.

Deathwatch

Mission Based, high power.

"Go strange and interesting places. Meet strange and interesting people and xenos. Then, kill them all for the God Emperor."

This game is fairly useful in that it provides the swarm rules, and makes it possible to play out larger scale military actions in a reasonable time.

The lack of real choice in character types, and the even higher than Rogue Trader power levels, combine to make this game particularly prone to devolving to a bug-hunt of the week mode.

Threats tend to be quite high powered, quite numerous, or both, this could spell lethality... were it not for insanely high armor and toughness.

Black Crusade

Power Level moderate to high.

This is the one I know the least about - the power level is about on par with Rogue Trader, and it appears to be advancement focused.

Note that all the example characters are chaos worshipers of various sorts.

Only War

Power Level moderate. Mission oriented. As of this writing, I've only seen the beta and the quick-play demo module.

The sample adventure is a flight before a "cleansing"... but there is plenty of potential for other mission types.

Characters are a somewhat narrow bunch of archetypes, but there is more variability than in Deathwatch.

Threats are fairly reasonable for the toughness and armor.

Combinations

It's easy enough to combine Rogue Trader and Dark Heresy - Dark Heresy Rank 7+ characters fit in just fine.

Deathwatch characters, if the Deathwatch package is left off, can be used as line marines assigned to Rogue Trader ships or to an inquisitor's team, but will be the combat gurus.

Only War Characters, while tougher than Dark Heresy, can be used with them with little effort. While weaker than Rogue Trader characters, given a few levels, they'll fit right in as the hired (or assigned) muscle.

Black Crusade characters won't be accepted in most Imperial settings... but any of the other types could, if they have fallen, fit in with a Black Crusade game.

Lethality

The trick is scaling the threats in whichever game or combination one runs.

Note that only Dark Heresy focuses on cash - Deathwatch, Rogue Trader and Only War abstract out access to new gear, so making things available is a real possibility for balancing things out.